fetchmail



fetchmail(1)                                                      fetchmail(1)




NAME

       fetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-capable server



SYNOPSIS

       fetchmail [option...] [mailserver...]
       fetchmailconf



DESCRIPTION

       fetchmail  is  a mail-retrieval and forwarding utility; it fetches mail
       from  remote  mailservers  and  forwards  it  to  your  local  (client)
       machine’s  delivery  system.   You  can  then handle the retrieved mail
       using normal mail user agents such as mutt(1), elm(1) or Mail(1).   The
       fetchmail utility can be run in a daemon mode to repeatedly poll one or
       more systems at a specified interval.

       The fetchmail program can gather mail from servers  supporting  any  of
       the  common  mail-retrieval protocols: POP2, POP3, IMAP2bis, IMAP4, and
       IMAPrev1.  It can also use the ESMTP ETRN  extension  and  ODMR.   (The
       RFCs  describing all these protocols are listed at the end of this man-
       ual page.)

       While fetchmail is primarily intended to be used over on-demand  TCP/IP
       links  (such  as  SLIP  or PPP connections), it may also be useful as a
       message transfer agent for sites which refuse for security  reasons  to
       permit (sender-initiated) SMTP transactions with sendmail.

       As each message is retrieved fetchmail normally delivers it via SMTP to
       port 25 on the machine it is running on (localhost), just as though  it
       were  being passed in over a normal TCP/IP link.  The mail will then be
       delivered locally via your system’s MDA (Mail Delivery  Agent,  usually
       sendmail(8)  but  your  system  may  use a different one such as smail,
       mmdf, exim, or qmail).  All the delivery-control  mechanisms  (such  as
       .forward  files)  normally  available through your system MDA and local
       delivery agents will therefore work automatically.

       If no port 25 listener is available, but your  fetchmail  configuration
       was  told  about  a  reliable local MDA, it will use that MDA for local
       delivery instead.  At build time, fetchmail  normally  looks  for  exe-
       cutable procmail(1) and sendmail(1) binaries.

       If  the  program fetchmailconf is available, it will assist you in set-
       ting up and editing a fetchmailrc configuration.  It runs under  X  and
       requires that the language Python and the Tk toolkit be present on your
       system.  If you are first setting up fetchmail for single-user mode, it
       is recommended that you use Novice mode.  Expert mode provides complete
       control of fetchmail configuration, including the  multidrop  features.
       In  either  case, the ‘Autoprobe’ button will tell you the most capable
       protocol a given mailserver supports, and warn you of  potential  prob-
       lems with that server.



GENERAL OPERATION

       The  behavior  of fetchmail is controlled by command-line options and a
       run control file, ~/.fetchmailrc, the syntax of which we describe in  a
       later  section  (this  file  is  what the fetchmailconf program edits).
       Command-line options override ~/.fetchmailrc declarations.

       Each server name that you specify following the options on the  command
       line  will be queried.  If you don’t specify any servers on the command
       line, each ‘poll’ entry in your ~/.fetchmailrc file will be queried.

       To facilitate the use of fetchmail in scripts and pipelines, it returns
       an appropriate exit code upon termination -- see EXIT CODES below.

       The  following  options modify the behavior of fetchmail.  It is seldom
       necessary to specify any of these once you have a working  .fetchmailrc
       file set up.

       Almost  all  options  have a corresponding keyword which can be used to
       declare them in a .fetchmailrc file.

       Some special options are not covered here, but are  documented  instead
       in sections on AUTHENTICATION and DAEMON MODE which follow.

   General Options
       -V | --version
              Displays the version information for your copy of fetchmail.  No
              mail fetch is performed.  Instead, for  each  server  specified,
              all  the  option information that would be computed if fetchmail
              were connecting to that server is displayed.  Any non-printables
              in  passwords  or other string names are shown as backslashed C-
              like escape sequences.  This option is useful for verifying that
              your options are set the way you want them.

       -c | --check
              Return  a status code to indicate whether there is mail waiting,
              without actually fetching  or  deleting  mail  (see  EXIT  CODES
              below).  This option turns off daemon mode (in which it would be
              useless).  It doesn’t play well with queries to multiple  sites,
              and doesn’t work with ETRN or ODMR.  It will return a false pos-
              itive if you leave read but undeleted mail in your server  mail-
              box  and  your  fetch protocol can’t tell kept messages from new
              ones.  This means it will work with IMAP, not  work  with  POP2,
              and may occasionally flake out under POP3.

       -s | --silent
              Silent  mode.   Suppresses all progress/status messages that are
              normally echoed to standard output during a fetch (but does  not
              suppress actual error messages).  The --verbose option overrides
              this.

       -v | --verbose
              Verbose mode.  All control messages passed between fetchmail and
              the  mailserver are echoed to stdout.  Overrides --silent.  Dou-
              bling this option (-v -v) causes extra diagnostic information to
              be printed.

   Disposal Options
       -a | --all
              (Keyword:  fetchall)  Retrieve  both old (seen) and new messages
              from the mailserver.  The default is to fetch only messages  the
              server has not marked seen.  Under POP3, this option also forces
              the use of RETR rather  than  TOP.   Note  that  POP2  retrieval
              behaves  as  though  --all  is  always on (see RETRIEVAL FAILURE
              MODES below) and this option does not work with ETRN or ODMR.

       -k | --keep
              (Keyword:  keep)  Keep  retrieved   messages   on   the   remote
              mailserver.   Normally,  messages are deleted from the folder on
              the mailserver after they have been retrieved.   Specifying  the
              keep  option  causes retrieved messages to remain in your folder
              on the mailserver.  This option does not work with ETRN or ODMR.

       -K | --nokeep
              (Keyword:  nokeep)  Delete  retrieved  messages  from the remote
              mailserver.  This option forces retrieved mail  to  be  deleted.
              It may be useful if you have specified a default of keep in your
              .fetchmailrc.  This option is forced on with ETRN and ODMR.

       -F | --flush
              POP3/IMAP only.  Delete old (previously retrieved) messages from
              the  mailserver before retrieving new messages. This option does
              not work with ETRN or ODMR.  Warning: if your  local  MTA  hangs
              and  fetchmail  is  aborted, the next time you run fetchmail, it
              will delete mail that was never  delivered  to  you.   What  you
              probably want is the default setting: if you don’t specify ‘-k’,
              then fetchmail will automatically delete messages after success-
              ful delivery.

   Protocol and Query Options
       -p <proto> | --protocol <proto>
              (Keyword:  proto[col]) Specify the protocol to use when communi-
              cating with the remote mailserver.  If no protocol is specified,
              the default is AUTO.  proto may be one of the following:

              AUTO   Tries  IMAP,  POP3,  and  POP2 (skipping any of these for
                     which support has not been compiled in).

              POP2   Post Office Protocol 2

              POP3   Post Office Protocol 3

              APOP   Use POP3 with old-fashioned MD5-challenge authentication.

              RPOP   Use POP3 with RPOP authentication.

              KPOP   Use POP3 with Kerberos V4 authentication on port 1109.

              SDPS   Use POP3 with Demon Internet’s SDPS extensions.

              IMAP   IMAP2bis,  IMAP4,  or  IMAP4rev1  (fetchmail  autodetects
                     their capabilities).

              ETRN   Use the ESMTP ETRN option.

              ODMR   Use the the On-Demand Mail Relay ESMTP profile.

       All these alternatives work in basically the  same  way  (communicating
       with standard server daemons to fetch mail already delivered to a mail-
       box on the server) except ETRN and ODMR.  The ETRN mode allows  you  to
       ask  a compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
       higher) to immediately open a sender-SMTP  connection  to  your  client
       machine and begin forwarding any items addressed to your client machine
       in the server’s queue of undelivered mail.   The ODMR mode requires  an
       ODMR-capable  server  and  works similarly to ETRN, except that it does
       not require the client machine to have a static DNS.

       -U | --uidl
              (Keyword: uidl) Force  UIDL  use  (effective  only  with  POP3).
              Force client-side tracking of ‘newness’ of messages (UIDL stands
              for ‘‘unique ID listing’’ and is  described  in  RFC1725).   Use
              with  ‘keep’ to use a mailbox as a baby news drop for a group of
              users. The fact that seen messages are skipped is logged, unless
              error  logging  is  done  through syslog while running in daemon
              mode.


       -P <portnumber> | --port <portnumber>
              (Keyword: port) The port option permits you to specify a  TCP/IP
              port to connect on.  This option will seldom be necessary as all
              the supported protocols have well-established default port  num-
              bers.

       --principal <principal>
              (Keyword: principal) The principal option permits you to specify
              a service principal for mutual authentication.  This is applica-
              ble to POP3 or IMAP with Kerberos authentication.

       -t <seconds> | --timeout <seconds>
              (Keyword:  timeout)  The  timeout  option  allows  you  to set a
              server-nonresponse timeout in seconds.  If a mailserver does not
              send  a  greeting  message  or respond to commands for the given
              number of seconds, fetchmail will hang up on it.  Without such a
              timeout  fetchmail  might  hang  up indefinitely trying to fetch
              mail from a down host.  This would be particularly annoying  for
              a  fetchmail  running in background.  There is a default timeout
              which fetchmail -V will report.  If a given connection  receives
              too  many  timeouts  in  succession,  fetchmail will consider it
              wedged and stop retrying, the calling user will be  notified  by
              email if this happens.

       --plugin <command>
              (Keyword:  plugin) The plugin option allows you to use an exter-
              nal program to establish the TCP connection.  This is useful  if
              you  want  to  use  socks,  SSL, ssh, or need some special fire-
              walling setup.  The program will be looked up in $PATH  and  can
              optionally  be  passed  the hostname and port as arguments using
              "%h" and "%p" respectively (note that the interpolation logic is
              rather  primitive, and these token must be bounded by whitespace
              or beginning of string or end of string).  Fetchmail will  write
              to the plugin’s stdin and read from the plugin’s stdout.

       --plugout <command>
              (Keyword:  plugout)  Identical  to  the plugin option above, but
              this one is used for the SMTP connections (which  will  probably
              not need it, so it has been separated from plugin).

       -r <name> | --folder <name>
              (Keyword:  folder[s]) Causes a specified non-default mail folder
              on the mailserver (or comma-separated list  of  folders)  to  be
              retrieved.   The  syntax of the folder name is server-dependent.
              This option is not available under POP3, ETRN, or ODMR.

       --tracepolls
              (Keyword: tracepolls) Tell fetchail to poll trace information in
              the  form ‘polling %s account %s’ to the Received line it gener-
              ates, where the %s parts are replaced by the user’s remote  name
              and  the  poll label (the Received header also normally includes
              the server’s truename).  This can be used to facilate mail  fil-
              tering based on the account it is being received from.

       --ssl  (Keyword:  ssl)  Causes  the connection to the mail server to be
              encrypted via SSL.  Connect to the server  using  the  specified
              base  protocol  over  a  connection secured by SSL.  SSL support
              must be present at the server.  If no  port  is  specified,  the
              connection  is  attempted to the well known port of the SSL ver-
              sion of the base protocol.  This is generally a  different  port
              than the port used by the base protocol.  For IMAP, this is port
              143 for the clear protocol and port 993 for the SSL secured pro-
              tocol.

       --sslcert <name>
              (Keyword:  sslcert)  Specifies  the file name of the client side
              public SSL certificate.  Some SSL encrypted servers may  require
              client  side  keys and certificates for authentication.  In most
              cases, this is optional.  This specifies  the  location  of  the
              public key certificate to be presented to the server at the time
              the SSL session is established.  It is not required (but may  be
              provided)  if  the server does not require it.  Some servers may
              require it, some servers may request it but not require it,  and
              some servers may not request it at all.  It may be the same file
              as the private key (combined key and certificate file) but  this
              is not recommended.

       --sslkey <name>
              (Keyword:  sslkey)  Specifies  the  file name of the client side
              private SSL key.  Some SSL encrypted servers may require  client
              side  keys  and certificates for authentication.  In most cases,
              this is optional.  This specifies the location  of  the  private
              key  used  to  sign transactions with the server at the time the
              SSL session is established.  It is not required (but may be pro-
              vided)  if  the  server  does  not require it.  Some servers may
              require it, some servers may request it but not require it,  and
              some servers may not request it at all.  It may be the same file
              as the public key (combined key and certificate file)  but  this
              is  not  recommended.   If  a password is required to unlock the
              key, it will be prompted for at the time just  prior  to  estab-
              lishing  the session to the server.  This can cause some compli-
              cations in daemon mode.

       --sslproto <name>
              (Keyword: sslproto) Forces an ssl protocol. Possible values  are
              ‘ssl2’,  ‘ssl3’  and  ‘tls1’.  Try this if the default handshake
              does not work for your server.

       --sslcertck
              (Keyword: sslcertck) Causes  fetchmail  to  strictly  check  the
              server  certificate  against a set of local trusted certificates
              (see the sslcertpath option). If the server certificate  is  not
              signed  by one of the trusted ones (directly or indirectly), the
              SSL connection will fail. This checking should  prevent  man-in-
              the-middle  attacks  against  the SSL connection. Note that CRLs
              are seemingly not currently supported by OpenSSL in  certificate
              verification!  Your  system  clock should be reasonably accurate
              when using this option!

       --sslcertpath <directory>
              (Keyword: sslcertpath) Sets the directory fetchmail uses to look
              up  local certificates. The default is your OpenSSL default one.
              The directory must be hashed as OpenSSL expects it - every  time
              you  add  or  modify a certificate in the directory, you need to
              use the c_rehash tool (which comes with OpenSSL  in  the  tools/
              subdirectory).

       --sslfingerprint
              (Keyword:  sslfingerprint) Specify the fingerprint of the server
              key (an MD5 hash of the key) in hexadecimal notation with colons
              separating  groups  of two digits. The letter hex digits must be
              in upper case. This is the default format OpenSSL uses, and  the
              one fetchmail uses to report the fingerprint when an SSL connec-
              tion is established. When this is specified, fetchmail will com-
              pare the server key fingerprint with the given one, and the con-
              nection will fail if they do not match. This can be used to pre-
              vent man-in-the-middle attacks.

   Delivery Control Options
       -S <hosts> | --smtphost <hosts>
              (Keyword:  smtp[host])  Specify  a hunt list of hosts to forward
              mail to (one or  more  hostnames,  comma-separated).  Hosts  are
              tried  in  list order; the first one that is up becomes the for-
              warding target for the current run.   Normally,  ‘localhost’  is
              added  to the end of the list as an invisible default.  However,
              when using Kerberos authentication, the FQDN of the machine run-
              ning  fetchmail  is added to the end of the list as an invisible
              default. Each hostname may have a port number following the host
              name.   The  port  number  is  separated from the host name by a
              slash; the default port is 25 (or ‘‘smtp’’ under IPv6).  If  you
              specify  an  absolute  pathname (beginning with a /), it will be
              interpreted as the name of a UNIX socket accepting LMTP  connec-
              tions (such as is supported by the Cyrus IMAP daemon) Example:

                   --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp

              This  option  can  be  used with ODMR, and will make fetchmail a
              relay between the ODMR server and SMTP or LMTP receiver.

       --fetchdomains <hosts>
              (Keyword: fetchdomains) In ETRN or ODMR mode, this option speci-
              fies  the  list  of domains the server should ship mail for once
              the connection is turned around.  The default is the FQDN of the
              machine running fetchmail.

       -D <domain> | --smtpaddress <domain>
              (Keyword:  smtpaddress)  Specify  the  domain  to be appended to
              addresses in RCPT TO lines shipped to SMTP. The name of the SMTP
              server (as specified by --smtphost, or defaulted to "localhost")
              is used when this is not specified.

       --smtpname <user@domain>
              (Keyword: smtpname) Specify the domain and user  to  be  put  in
              RCPT  TO lines shipped to SMTP.  The default user is the current
              local user.

       -Z <nnn> | --antispam <nnn[, nnn]...>
              (Keyword: antispam) Specifies the list of  numeric  SMTP  errors
              that  are  to  be  interpreted as a spam-block response from the
              listener.  A value of -1 disables this option.  For the command-
              line option, the list values should be comma-separated.

       -m <command> | --mda <command>
              (Keyword:  mda)  You  can  force  mail  to  be  passed to an MDA
              directly (rather than forwarded to port 25) with the --mda or -m
              option.   To  avoid  losing mail, use this option only with MDAs
              like procmail or sendmail that return a nonzero status on  disk-
              full  and  other  resource-exhaustion errors; the nonzero status
              tells fetchmail that delivery failed and  prevents  the  message
              from  being  deleted off the server.  If fetchmail is running as
              root, it sets its userid to that of the target user while deliv-
              ering   mail   through   an   MDA.    Some   possible  MDAs  are
              "/usr/sbin/sendmail  -i  -f  %F  %T",   "/usr/bin/deliver"   and
              "/usr/bin/procmail  -d  %T" (but the latter is usually redundant
              as it’s what SMTP listeners normally forward to).  Local  deliv-
              ery addresses will be inserted into the MDA command wherever you
              place a %T; the mail message’s From  address  will  be  inserted
              where you place an %F.  In both cases the addresses are enclosed
              in single quotes (’), after removing any single quotes they  may
              contain,  before the MDA command is passed to the shell.  Do not
              use an MDA invocation like "sendmail -i -t" that  dispatches  on
              the  contents  of To/Cc/Bcc, it will create mail loops and bring
              the just wrath of many postmasters down upon your  head.   Also,
              do  not  try to combine multidrop mode with an MDA such as proc-
              mail that can only accept one addressee; you will lose.

       --lmtp (Keyword: lmtp) Cause delivery via  LMTP  (Local  Mail  Transfer
              Protocol).   A service port must be explicitly specified (with a
              slash suffix) on each host in the smtphost  hunt  list  if  this
              option is selected; the default port 25 will (in accordance with
              RFC 2033) not be accepted.

       --bsmtp <filename>
              (keyword: bsmtp) Append fetched mail to a BSMTP file.  This sim-
              ply  contains the SMTP commands that would normally be generated
              by fetchmail when passing mail to an SMTP listener  daemon.   An
              argument  of  ‘-’ causes the mail to be written to standard out-
              put.  Note that fetchmail’s reconstruction of MAIL FROM and RCPT
              TO  lines is not guaranteed correct; the caveats discussed under
              THE USE AND ABUSE OF MULTIDROP MAILBOXES below apply.

   Resource Limit Control Options
       -l <maxbytes> | --limit <maxbytes>
              (Keyword: limit) Takes a maximum octet size argument.   Messages
              larger  than  this  size will not be fetched and will be left on
              the server (in foreground sessions, the progress  messages  will
              note  that they are "oversized").  If the fetch protocol permits
              (in particular, under IMAP or POP3 without the fetchall  option)
              the  message  will  not  be marked seen An explicit --limit of 0
              overrides any limits set in your run control file.  This  option
              is intended for those needing to strictly control fetch time due
              to expensive and variable phone rates.  Combined  with  --flush,
              it can be used to delete oversized messages waiting on a server.
              In daemon mode, oversize notifications are mailed to the calling
              user  (see  the  --warnings  option).  This option does not work
              with ETRN or ODMR.

       -w <interval> | --warnings <interval>
              (Keyword: warnings) Takes an interval in seconds.  When you call
              fetchmail  with  a  ‘limit’ option in daemon mode, this controls
              the interval at which  warnings  about  oversized  messages  are
              mailed  to the calling user (or the user specified by the ‘post-
              master’ option).  One such notification is always mailed at  the
              end  of  the  the  first  poll  that  the  oversized  message is
              detected.  Thereafter, renotification is suppressed until  after
              the  warning  interval elapses (it will take place at the end of
              the first following poll).

       -b <count> | --batchlimit <count>
              (Keyword: batchlimit) Specify the  maximum  number  of  messages
              that  will  be shipped to an SMTP listener before the connection
              is deliberately torn down and rebuilt (defaults to 0, meaning no
              limit).   An explicit --batchlimit of 0 overrides any limits set
              in your run control file.  While sendmail(8) normally  initiates
              delivery  of  a  message immediately after receiving the message
              terminator, some SMTP listeners are not so  prompt.   MTAs  like
              smail(8)  may  wait  till  the  delivery  socket is shut down to
              deliver.  This may produce annoying  delays  when  fetchmail  is
              processing  very large batches.  Setting the batch limit to some
              nonzero size will prevent these delays.  This  option  does  not
              work with ETRN or ODMR.

       -B <number> | --fetchlimit <number>
              (Keyword: fetchlimit) Limit the number of messages accepted from
              a given server in a single poll.  By default there is no  limit.
              An  explicit  --fetchlimit of 0 overrides any limits set in your
              run control file.  This option does not work with ETRN or  ODMR.

       --fetchsizelimit <number>
              (Keyword:  fetchsizelimit) Limit the number of sizes of messages
              accepted from a given server  in  a  single  transaction.   This
              option  is useful in reducing the delay in downloading the first
              mail when there are too many mails in the mailbox.  By  default,
              the  limit is 100.  If set to 0, sizes of all messages are down-
              loaded at the start.  This option does not  work  with  ETRN  or
              ODMR.  For POP3, the only valid non-zero value is 1.

       --fastuidl <number>
              (Keyword: fastuidl) Do a binary instead of linear search for the
              first unseen UID. Binary search avoids downloading the  UIDs  of
              all  mails.  This  saves  time (especially in daemon mode) where
              downloading the same set of UIDs in each  poll  is  a  waste  of
              bandwidth.  The  number ‘n’ indicates how rarely a linear search
              should be done. In daemon mode, linear search is used once  fol-
              lowed  by  binary searches in ‘n-1’ polls if ‘n’ is greater than
              1; binary search is always used if ‘n’ is 1;  linear  search  is
              always  used  if  ‘n’ is 0. In non-daemon mode, binary search is
              used if ‘n’ is 1; otherwise linear search is used.  This  option
              works with POP3 only.

       -e <count> | --expunge <count>
              (keyword:  expunge) Arrange for deletions to be made final after
              a given number of messages.  Under POP2 or POP3, fetchmail  can-
              not  make  deletions  final  without sending QUIT and ending the
              session -- with this option on, fetchmail will break a long mail
              retrieval  session into multiple subsessions, sending QUIT after
              each sub-session. This is a good defense against line  drops  on
              POP3  servers that do not do the equivalent of a QUIT on hangup.
              Under IMAP, fetchmail normally issues an EXPUNGE  command  after
              each  deletion in order to force the deletion to be done immedi-
              ately.  This is safest when your connection  to  the  server  is
              flaky and expensive, as it avoids resending duplicate mail after
              a line hit.  However, on large mailboxes  the  overhead  of  re-
              indexing after every message can slam the server pretty hard, so
              if your connection is reliable it is good to  do  expunges  less
              frequently.   Also  note  that some servers enforce a delay of a
              few seconds after each quit, so fetchmail may not be able to get
              back  in immediately after an expunge -- you may see "lock busy"
              errors if this happens. If you specify this option to an integer
              N,  it  tells  fetchmail  to  only  issue  expunges on every Nth
              delete.  An argument of zero suppresses expunges entirely (so no
              expunges at all will be done until the end of run).  This option
              does not work with ETRN or ODMR.

   Authentication Options
       -u <name> | --username <name>
              (Keyword: user[name]) Specifies the user  identification  to  be
              used  when  logging  in to the mailserver.  The appropriate user
              identification is both server and user-dependent.   The  default
              is  your login name on the client machine that is running fetch-
              mail.  See USER AUTHENTICATION below for a complete description.

       -I <specification> | --interface <specification>
              (Keyword: interface) Require that a specific interface device be
              up and have a specific local or remote  IP  address  (or  range)
              before  polling.   Frequently fetchmail is used over a transient
              point-to-point TCP/IP link established directly to a  mailserver
              via SLIP or PPP.  That is a relatively secure channel.  But when
              other TCP/IP routes to the mailserver exist (e.g. when the  link
              is  connected  to  an alternate ISP), your username and password
              may be vulnerable to snooping (especially when daemon mode auto-
              matically polls for mail, shipping a clear password over the net
              at predictable intervals).  The --interface option may  be  used
              to  prevent  this.   When the specified link is not up or is not
              connected to a matching IP address,  polling  will  be  skipped.
              The format is:

                   interface/iii.iii.iii.iii/mmm.mmm.mmm.mmm

              The  field  before  the  first slash is the interface name (i.e.
              sl0, ppp0 etc.).  The field  before  the  second  slash  is  the
              acceptable  IP  address.   The field after the second slash is a
              mask which specifies a range of IP addresses to accept.   If  no
              mask  is  present  255.255.255.255  is  assumed  (i.e.  an exact
              match).  This option is currently only supported under Linux and
              FreeBSD.  Please  see  the monitor section for below for FreeBSD
              specific information.

       -M <interface> | --monitor <interface>
              (Keyword: monitor) Daemon mode can cause transient  links  which
              are  automatically taken down after a period of inactivity (e.g.
              PPP links) to remain up indefinitely.  This option identifies  a
              system  TCP/IP  interface  to  be monitored for activity.  After
              each poll interval, if the link is up but no other activity  has
              occurred  on  the link, then the poll will be skipped.  However,
              when fetchmail is woken up by a signal,  the  monitor  check  is
              skipped  and the poll goes through unconditionally.  This option
              is currently only supported under Linux and  FreeBSD.   For  the
              monitor  and  interface options to work for non root users under
              FreeBSD, the fetchmail binary must be installed SGID kmem.  This
              would  be a security hole, but fetchmail runs with the effective
              GID set to that of the kmem group only when  interface  data  is
              being collected.

       --auth <type>
              (Keyword:  auth[enticate]) This option permits you to specify an
              authentication type (see USER AUTHENTICATION below for details).
              The possible values are any, ‘password’, ‘kerberos_v5’ and ‘ker-
              beros’ (or, for excruciating exactness, ‘kerberos_v4’),  gssapi,
              cram-md5,  otp, ntlm, and ssh.  When any (the default) is speci-
              fied, fetchmail tries first methods that don’t require  a  pass-
              word  (GSSAPI, KERBEROS_IV); then it looks for methods that mask
              your password (CRAM-MD5, X-OTP, NTLM); and only  if  the  server
              doesn’t  support  any  of  those  will  it ship your password en
              clair.  Other values may be used to force various authentication
              methods  (ssh  suppresses authentication).  Any value other than
              password, cram-md5, ntlm or otp  suppresses  fetchmail’s  normal
              inquiry  for a password.  Specify ssh when you are using an end-
              to-end secure connection such as an ssh tunnel;  specify  gssapi
              or  kerberos_v4 if you are using a protocol variant that employs
              GSSAPI or K4.  Choosing KPOP protocol automatically selects Ker-
              beros authentication.  This option does not work with ETRN.

   Miscellaneous Options
       -f <pathname> | --fetchmailrc <pathname>
              Specify  a  non-default  name for the ~/.fetchmailrc run control
              file.  The pathname argument must be either "-" (a single  dash,
              meaning  to  read  the  configuration  from standard input) or a
              filename.  Unless the --version option is also on, a named  file
              argument   must   have   permissions  no  more  open  than  0600
              (u=rw,g=,o=) or else be /dev/null.

       -i <pathname> | --idfile <pathname>
              (Keyword: idfile) Specify an alternate name  for  the  .fetchids
              file used to save POP3 UIDs.

       -n | --norewrite
              (Keyword:  no rewrite) Normally, fetchmail edits RFC-822 address
              headers (To, From, Cc, Bcc, and Reply-To)  in  fetched  mail  so
              that  any  mail  IDs  local  to  the server are expanded to full
              addresses (@ and the mailserver hostname  are  appended).   This
              enables replies on the client to get addressed correctly (other-
              wise your mailer might think they should be addressed  to  local
              users  on  the  client  machine!).   This  option  disables  the
              rewrite.  (This option is provided  to  pacify  people  who  are
              paranoid  about having an MTA edit mail headers and want to know
              they can prevent it, but it is generally  not  a  good  idea  to
              actually  turn  off  rewrite.)   When  using  ETRN  or ODMR, the
              rewrite option is ineffective.

       -E <line> | --envelope <line>
              (Keyword: envelope) This option  changes  the  header  fetchmail
              assumes  will carry a copy of the mail’s envelope address.  Nor-
              mally this is ‘X-Envelope-To’ but as this header  is  not  stan-
              dard,  practice  varies. See the discussion of multidrop address
              handling  below.   As  a  special  case,  ‘envelope  "Received"’
              enables  parsing  of sendmail-style Received lines.  This is the
              default, and it should not be necessary unless you have globally
              disabled Received parsing with ‘no envelope’ in the .fetchmailrc
              file.

       -Q <prefix> | --qvirtual <prefix>
              (Keyword: qvirtual) The string prefix assigned  to  this  option
              will be removed from the user name found in the header specified
              with the envelope option (before doing multidrop name mapping or
              localdomain  checking,  if either is applicable). This option is
              useful if you are using fetchmail to collect  the  mail  for  an
              entire  domain  and your ISP (or your mail redirection provider)
              is using qmail.  One of the basic features of qmail is the

              ‘Delivered-To:’

              message header.  Whenever qmail delivers a message  to  a  local
              mailbox it puts the username and hostname of the envelope recip-
              ient on this line.  The major reason for this is to prevent mail
              loops.   To  set  up qmail to batch mail for a disconnected site
              the ISP-mailhost will have normally put that site in its ‘Virtu-
              alhosts’  control  file  so  it  will  add  a prefix to all mail
              addresses for this site. This results in  mail  sent  to  ’user-
              name@userhost.userdom.dom.com’  having a ‘Delivered-To:’ line of
              the form:

              Delivered-To: mbox-userstr-username@userhost.userdom.dom.com

              The ISP can make the ’mbox-userstr-’ prefix anything they choose
              but  a  string  matching the user host name is likely.  By using
              the option ‘envelope Delivered-To:’ you can make fetchmail reli-
              ably  identify  the original envelope recipient, but you have to
              strip the ‘mbox-userstr-’ prefix to deliver to the correct user.
              This is what this option is for.

       --configdump
              Parse   the  ~/.fetchmailrc  file,  interpret  any  command-line
              options specified, and dump a configuration report  to  standard
              output.  The configuration report is a data structure assignment
              in the language Python.  This option is meant to be used with an
              interactive ~/.fetchmailrc editor like fetchmailconf, written in
              Python.



USER AUTHENTICATION AND ENCRYPTION

       All modes except ETRN require  authentication  of  the  client  to  the
       server.   Normal user authentication in fetchmail is very much like the
       authentication mechanism of ftp(1).  The correct user-id  and  password
       depend upon the underlying security system at the mailserver.

       If  the mailserver is a Unix machine on which you have an ordinary user
       account, your regular login name and password are used with  fetchmail.
       If  you  use  the  same  login  name  on both the server and the client
       machines, you needn’t worry about specifying  a  user-id  with  the  -u
       option  -- the default behavior is to use your login name on the client
       machine as the user-id on the server machine.  If you use  a  different
       login  name  on the server machine, specify that login name with the -u
       option.  e.g. if your login name is ’jsmith’ on a machine named  ’mail-
       grunt’, you would start fetchmail as follows:

              fetchmail -u jsmith mailgrunt

       The  default behavior of fetchmail is to prompt you for your mailserver
       password before the connection is established.  This is the safest  way
       to  use  fetchmail  and  ensures that your password will not be compro-
       mised.  You may also specify your password in your ~/.fetchmailrc file.
       This is convenient when using fetchmail in daemon mode or with scripts.

       If you do not specify a password, and fetchmail cannot extract one from
       your ~/.fetchmailrc file, it will look for a ~/.netrc file in your home
       directory before requesting one interactively; if an entry matching the
       mailserver is found in that file, the password will be used.  Fetchmail
       first looks for a match on poll name; if it finds none, it checks for a
       match  on  via name.  See the ftp(1) man page for details of the syntax
       of the ~/.netrc file.  (This feature may allow you to avoid duplicating
       password information in more than one file.)

       On mailservers that do not provide ordinary user accounts, your user-id
       and password are usually assigned by the server administrator when  you
       apply  for  a mailbox on the server.  Contact your server administrator
       if you don’t know the correct user-id and  password  for  your  mailbox
       account.

       Early  versions  of  POP3  (RFC1081, RFC1225) supported a crude form of
       independent authentication using the  rhosts  file  on  the  mailserver
       side.   Under  this  RPOP  variant, a fixed per-user ID equivalent to a
       password was sent in clear over a link to a  reserved  port,  with  the
       command  RPOP  rather  than  PASS to alert the server that it should do
       special checking.  RPOP is supported  by  fetchmail  (you  can  specify
       ‘protocol RPOP’ to have the program send ‘RPOP’ rather than ‘PASS’) but
       its use is strongly  discouraged.   This  facility  was  vulnerable  to
       spoofing and was withdrawn in RFC1460.

       RFC1460  introduced  APOP authentication.  In this variant of POP3, you
       register an APOP password on your server host (the program to  do  this
       with  on  the  server is probably called popauth(8)).  You put the same
       password in your ~/.fetchmailrc file.  Each time fetchmail logs in,  it
       sends  a  cryptographically secure hash of your password and the server
       greeting time to the server, which can verify it by checking its autho-
       rization database.

       If  your fetchmail was built with Kerberos support and you specify Ker-
       beros authentication (either with --auth  or  the  .fetchmailrc  option
       authenticate kerberos_v4) it will try to get a Kerberos ticket from the
       mailserver at the start of each query.  Note: if either the pollnane or
       via  name  is ‘hesiod’, fetchmail will try to use Hesiod to look up the
       mailserver.

       If you use POP3 or IMAP  with  GSSAPI  authentication,  fetchmail  will
       expect  the  server to have RFC1731- or RFC1734-conformant GSSAPI capa-
       bility, and will use it.  Currently this has only been tested over Ker-
       beros  V,  so you’re expected to already have a ticket-granting ticket.
       You may pass a username different from your principal  name  using  the
       standard --user command or by the .fetchmailrc option user.

       If  your IMAP daemon returns the PREAUTH response in its greeting line,
       fetchmail will notice this and skip  the  normal  authentication  step.
       This  can  be useful, e.g. if you start imapd explicitly using ssh.  In
       this case you can declare the authentication value ‘ssh’ on  that  site
       entry  to stop .fetchmail from asking you for a password when it starts
       up.

       If you are using POP3, and the server issues a one-time-password  chal-
       lenge conforming to RFC1938, fetchmail will use your password as a pass
       phrase to generate the required response. This avoids  sending  secrets
       over the net unencrypted.

       Compuserve’s  RPA authentication (similar to APOP) is supported. If you
       compile in the support, fetchmail will try  to  perform  an  RPA  pass-
       phrase  authentication instead of sending over the password en clair if
       it detects "@compuserve.com" in the hostname.

       If you  are  using  IMAP,  Microsoft’s  NTLM  authentication  (used  by
       Microsoft Exchange) is supported. If you compile in the support, fetch-
       mail will try to perform an NTLM  authentication  (instead  of  sending
       over  the  password  en clair) whenever the server returns AUTH=NTLM in
       its capability response. Specify a user option value  that  looks  like
       ‘user@domain’:  the  part  to  the  left of the @ will be passed as the
       username and the part to the right as the NTLM domain.

       If you are using IPsec, the -T (--netsec) option can be used to pass an
       IP  security  request  to be used when outgoing IP connections are ini-
       tialized.  You can also do this using the ‘netsec’ server option in the
       .fetchmailrc file.  In either case, the option value is a string in the
       format accepted by  the  net_security_strtorequest()  function  of  the
       inet6_apps library.

       You  can  access SSL encrypted services by specifying the --ssl option.
       You can also do this using the "ssl" server option in the  .fetchmailrc
       file.   With  SSL encryption enabled, queries are initiated over a con-
       nection after negotiating an SSL session.  Some services, such as  POP3
       and IMAP, have different well known ports defined for the SSL encrypted
       services.  The encrypted ports will be selected automatically when  SSL
       is enabled and no explicit port is specified.

       When  connecting to an SSL encrypted server, the server presents a cer-
       tificate to the client for validation.  The certificate is  checked  to
       verify  that the common name in the certificate matches the name of the
       server being contacted and that the effective and expiration  dates  in
       the  certificate  indicate that it is currently valid.  If any of these
       checks fail, a warning message is printed, but the  connection  contin-
       ues.  The server certificate does not need to be signed by any specific
       Certifying Authority and may be a "self-signed" certificate.

       Some SSL encrypted servers may request a client  side  certificate.   A
       client  side  public  SSL certificate and private SSL key may be speci-
       fied.  If requested by the server, the client certificate  is  sent  to
       the  server  for  validation.   Some servers may require a valid client
       certificate and may refuse connections if a certificate is not provided
       or  if  the  certificate is not valid.  Some servers may require client
       side certificates be signed by a recognized Certifying Authority.   The
       format  for the key files and the certificate files is that required by
       the underlying SSL libraries (OpenSSL in the general case).

       A word of care about the use of SSL: While above mentioned  setup  with
       self-signed  server  certificates  retrieved over the wires can protect
       you from a passive eavesdropper  it  doesn’t  help  against  an  active
       attacker.  It’s  clearly  an  improvement over sending the passwords in
       clear but you should be aware that a man-in-the-middle attack is  triv-
       ially   possible   (in   particular   with   tools   such   as  dsniff,
       http://www.monkey.org/~dugsong/dsniff/).  Use of  an  ssh  tunnel  (see
       below  for some examples) is preferable if you care seriously about the
       security of your mailbox.

       fetchmail also supports authentication  to  the  ESMTP  server  on  the
       client  side  according  to  RFC 2554.  You can specify a name/password
       pair to be used with the keywords ‘esmtpname’ and ‘esmtppassword’;  the
       former defaults to the username of the calling user.



DAEMON MODE

       The  --daemon <interval> or -d <interval> option runs fetchmail in dae-
       mon mode.  You must specify a  numeric  argument  which  is  a  polling
       interval in seconds.

       In  daemon  mode, fetchmail puts itself in background and runs forever,
       querying each specified host and then sleeping for  the  given  polling
       interval.

       Simply invoking

              fetchmail -d 900

       will,  therefore,  poll  all the hosts described in your ~/.fetchmailrc
       file (except those explicitly excluded with the ‘skip’ verb) once every
       fifteen minutes.

       It is possible to set a polling interval in your ~/.fetchmailrc file by
       saying ‘set daemon <interval>’, where <interval> is an  integer  number
       of seconds.  If you do this, fetchmail will always start in daemon mode
       unless you override it with the command-line option --daemon 0 or  -d0.

       Only  one  daemon process is permitted per user; in daemon mode, fetch-
       mail makes a per-user lockfile to guarantee this.

       Normally, calling fetchmail with a daemon in  the  background  sends  a
       wakeup  signal  to  the  daemon, forcing it to poll mailservers immedi-
       ately.  (The wakeup signal is SIGHUP if fetchmail is running  as  root,
       SIGUSR1  otherwise.)   The wakeup action also clears any ‘wedged’ flags
       indicating that connections have wedged due to failed authentication or
       multiple timeouts.

       The  option --quit will kill a running daemon process instead of waking
       it up (if there is no such process, fetchmail notifies  you).   If  the
       --quit  option  is the only command-line option, that’s all there is to
       it.

       The quit option may also be mixed with other command-line options;  its
       effect  is  to  kill  any  running  daemon  before doing what the other
       options specify in combination with the rc file.

       The -L <filename> or --logfile <filename> option (keyword: set logfile)
       allows  you  to  redirect status messages emitted while detached into a
       specified logfile (follow the option with the logfile name).  The  log-
       file  is  opened for append, so previous messages aren’t deleted.  This
       is primarily useful for debugging configurations.

       The --syslog option (keyword: set syslog) allows you to redirect status
       and error messages emitted to the syslog(3) system daemon if available.
       Messages are logged with an id of fetchmail, the facility LOG_MAIL, and
       priorities LOG_ERR, LOG_ALERT or LOG_INFO.  This option is intended for
       logging status and error messages which indicate the status of the dae-
       mon and the results while fetching mail from the server(s).  Error mes-
       sages for command line options and parsing the  .fetchmailrc  file  are
       still  written to stderr, or to the specified log file.  The --nosyslog
       option turns off use of syslog(3),  assuming  it’s  turned  on  in  the
       ~/.fetchmailrc  file,  or  that  the  -L or --logfile <file> option was
       used.

       The -N or --nodetach option suppresses backgrounding and detachment  of
       the daemon process from its control terminal.  This is primarily useful
       for debugging.  Note that this also causes the  logfile  option  to  be
       ignored (though perhaps it shouldn’t).

       Note  that  while  running  in  daemon  mode polling a POP2 or IMAP2bis
       server, transient errors (such as DNS  failures  or  sendmail  delivery
       refusals) may force the fetchall option on for the duration of the next
       polling cycle.  This is a robustness feature.  It means that if a  mes-
       sage is fetched (and thus marked seen by the mailserver) but not deliv-
       ered locally due to some transient error, it will be re-fetched  during
       the  next  poll  cycle.   (The IMAP logic doesn’t delete messages until
       they’re delivered, so this problem does not arise.)

       If you touch or change the ~/.fetchmailrc file while fetchmail is  run-
       ning in daemon mode, this will be detected at the beginning of the next
       poll cycle.  When  a  changed  ~/.fetchmailrc  is  detected,  fetchmail
       rereads  it and restarts from scratch (using exec(2); no state informa-
       tion is retained in the new instance).  Note also that if you break the
       ~/.fetchmailrc file’s syntax, the new instance will softly and silently
       vanish away on startup.



ADMINISTRATIVE OPTIONS

       The --postmaster <name> option (keyword: set postmaster) specifies  the
       last-resort  username  to which multidrop mail is to be forwarded if no
       matching local recipient can be found.  Normally this is just the  user
       who  invoked fetchmail.  If the invoking user is root, then the default
       of this option is the user ‘postmaster’.   Setting  postmaster  to  the
       empty string causes such mail to be discarded.

       The  --nobounce  option suppresses the normal action of bouncing errors
       back to the sender in an RFC1894-conformant error message.  If nobounce
       is on, the message will go to the postmaster instead.

       The --invisible option (keyword: set invisible) tries to make fetchmail
       invisible.  Normally, fetchmail behaves like any other MTA would --  it
       generates  a  Received header into each message describing its place in
       the chain of transmission, and tells the MTA it forwards  to  that  the
       mail  came  from  the  machine  fetchmail itself is running on.  If the
       invisible option is on, the Received header is suppressed and fetchmail
       tries  to  spoof  the MTA it forwards to into thinking it came directly
       from the mailserver host.

       The --showdots option (keyword: set showdots) forces fetchmail to  show
       progress  dots  even if the current tty is not stdout (for example log-
       files).  Starting with fetchmail version 5.3.0, progress dots are  only
       shown on stdout by default.

       By  specifying  the  --tracepolls  option, you can ask fetchmail to add
       information to the Received header on the form "polling {label} account
       {user}", where {label} is the account label (from the specified rcfile,
       normally ~/.fetchmailrc) and {user} is the username which  is  used  to
       log  on  to  the mail server. This header can be used to make filtering
       email where no useful header information is available and you want mail
       from  different  accounts  sorted into different mailboxes (this could,
       for example, occur if you have an account on the same server running  a
       mailing  list,  and are subscribed to the list using that account). The
       default is not adding any such header.  In .fetchmailrc, this is called
       ‘tracepolls’.



RETRIEVAL FAILURE MODES

       The protocols fetchmail uses to talk to mailservers are next to bullet-
       proof.  In normal operation forwarding to port 25, no message  is  ever
       deleted  (or  even marked for deletion) on the host until the SMTP lis-
       tener on the client side has acknowledged to fetchmail that the message
       has  been either accepted for delivery or rejected due to a spam block.

       When forwarding to an MDA, however, there is more possibility of error.
       Some MDAs are ‘safe’ and reliably return a nonzero status on any deliv-
       ery error, even one due to temporary resource limits.   The  well-known
       procmail(1) program is like this; so are most programs designed as mail
       transport agents, such as sendmail(1),  and  exim(1).   These  programs
       give  back a reliable positive acknowledgement and can be used with the
       mda option with no risk of mail loss.  Unsafe MDAs, though, may  return
       0 even on delivery failure.  If this happens, you will lose mail.

       The normal mode of fetchmail is to try to download only ‘new’ messages,
       leaving untouched  (and  undeleted)  messages  you  have  already  read
       directly  on  the server (or fetched with a previous fetchmail --keep).
       But you may find that messages you’ve already read on  the  server  are
       being  fetched  (and deleted) even when you don’t specify --all.  There
       are several reasons this can happen.

       One could be that you’re using POP2.  The  POP2  protocol  includes  no
       representation  of  ‘new’ or ‘old’ state in messages, so fetchmail must
       treat all messages as new all the time.  But POP2 is obsolete, so  this
       is unlikely.

       Under  POP3, blame RFC1725.  That version of the POP3 protocol specifi-
       cation removed the LAST command, and some POP servers  follow  it  (you
       can verify this by invoking fetchmail -v to the mailserver and watching
       the response to LAST early in the query).  The fetchmail code tries  to
       compensate by using POP3’s UID feature, storing the identifiers of mes-
       sages seen in each session until the next  session,  in  the  .fetchids
       file.  But this doesn’t track messages seen with other clients, or read
       directly with a mailer on the host but not deleted afterward.  A better
       solution would be to switch to IMAP.

       Another potential POP3 problem might be servers that insert messages in
       the middle of mailboxes (some VMS implementations of mail  are  rumored
       to do this).  The fetchmail code assumes that new messages are appended
       to the end of the mailbox; when this is not true it may treat some  old
       messages  as new and vice versa.  The only real fix for this problem is
       to  switch to IMAP.

       Yet another POP3 problem is that if they can’t make  tempfiles  in  the
       user’s home directory, some POP3 servers will hand back an undocumented
       response that causes fetchmail to spuriously report "No mail".

       The IMAP code uses the presence or absence of the server flag \Seen  to
       decide  whether or not a message is new.  Under Unix, it counts on your
       IMAP server to notice the BSD-style  Status  flags  set  by  mail  user
       agents  and  set  the  \Seen flag from them when appropriate.  All Unix
       IMAP servers we know of do this, though it’s not specified by the  IMAP
       RFCs.  If you ever trip over a server that doesn’t, the symptom will be
       that messages you have already read on your host will look new  to  the
       server.  In this (unlikely) case, only messages you fetched with fetch-
       mail --keep will be both undeleted and marked old.

       In ETRN and ODMR modes, fetchmail does not actually retrieve  messages;
       instead,  it  asks the server’s SMTP listener to start a queue flush to
       the client via SMTP.  Therefore it sends only undelivered messages.



SPAM FILTERING

       Many SMTP listeners allow administrators to set up ‘spam filters’  that
       block  unsolicited  email  from specified domains.  A MAIL FROM or DATA
       line that triggers this feature will  elicit  an  SMTP  response  which
       (unfortunately) varies according to the listener.

       Newer  versions  of  sendmail return an error code of 571.  This return
       value is blessed  by  RFC1893  as  "Delivery  not  authorized,  message
       refused".

       According  to RFC2821, the correct thing to return in this situation is
       550 "Requested action not taken: mailbox unavailable" (the  draft  adds
       "[E.g.,  mailbox  not  found, no access, or command rejected for policy
       reasons].").

       Older versions of the exim MTA return 501 "Syntax error  in  parameters
       or arguments".

       The postfix MTA runs 554 as an antispam response.

       Zmailer  may  reject  code with a 500 response (followed by an enhanced
       status code that contains more information).

       Return codes which fetchmail treats as antispam responses and  discards
       the  message can be set with the ‘antispam’ option.  This is one of the
       only three circumstance under which fetchmail ever discards  mail  (the
       others  are the 552 and 553 errors described below, and the suppression
       of multidropped messages with a message-ID already seen).

       If fetchmail is fetching from an IMAP  server,  the  antispam  response
       will be detected and the message rejected immediately after the headers
       have been fetched, without reading the message body.  Thus,  you  won’t
       pay for downloading spam message bodies.

       By default, the list of antispam responses is empty.

       If  the  spambounce option is on, mail that is spam-blocked triggers an
       RFC1892 bounce message informing the originator that we do  not  accept
       mail from it.



SMTP/ESMTP ERROR HANDLING

       Besides  the  spam-blocking  described  above,  fetchmail takes special
       actions on the following SMTP/ESMTP error responses

       452 (insufficient system storage)
            Leave the message in the server mailbox for later retrieval.

       552 (message exceeds fixed maximum message size)
            Delete the message from the server.  Send bounce-mail to the orig-
            inator.

       553 (invalid sending domain)
            Delete  the  message  from  the  server.   Don’t  even try to send
            bounce-mail to the originator.

       Other errors trigger bounce mail back to the originator.



THE RUN CONTROL FILE

       The preferred way to set up fetchmail is to write a  .fetchmailrc  file
       in  your  home directory (you may do this directly, with a text editor,
       or indirectly via fetchmailconf).  When there is a conflict between the
       command-line arguments and the arguments in this file, the command-line
       arguments take precedence.

       To protect the security of your passwords, when  --version  is  not  on
       your  ~/.fetchmailrc  may  not have more than 0600 (u=rw,g=,o=) permis-
       sions; fetchmail will complain and exit otherwise.

       You may read the .fetchmailrc file as a list of commands to be executed
       when fetchmail is called with no arguments.

   Run Control Syntax
       Comments begin with a ’#’ and extend through the end of the line.  Oth-
       erwise the file consists of a series of server entries or global option
       statements in a free-format, token-oriented syntax.

       There are four kinds of tokens: grammar keywords, numbers (i.e. decimal
       digit sequences), unquoted  strings,  and  quoted  strings.   A  quoted
       string  is  bounded  by  double  quotes and may contain whitespace (and
       quoted digits are treated as a string).   An  unquoted  string  is  any
       whitespace-delimited  token  that is neither numeric, string quoted nor
       contains the special characters ‘,’, ‘;’, ‘:’, or ‘=’.

       Any amount of whitespace separates tokens in  server  entries,  but  is
       otherwise  ignored.  You  may use standard C-style escapes (\n, \t, \b,
       octal, and hex) to embed non-printable characters or string  delimiters
       in strings.

       Each  server  entry  consists  of one of the keywords ‘poll’ or ‘skip’,
       followed by a server name, followed by server options, followed by  any
       number  of  user  descriptions.   Note: the most common cause of syntax
       errors is mixing up user and server options.

       For backward compatibility, the word ‘server’ is a synonym for  ‘poll’.

       You  can  use  the  noise  keywords  ‘and’, ‘with’, ‘has’, ‘wants’, and
       ‘options’ anywhere in an entry to make it  resemble  English.   They’re
       ignored, but but can make entries much easier to read at a glance.  The
       punctuation characters ’:’, ’;’ and ’,’ are also ignored.


   Poll vs. Skip
       The ‘poll’ verb tells fetchmail to query this host when it is run  with
       no  arguments.   The  ‘skip’ verb tells fetchmail not to poll this host
       unless it is explicitly named on the command line.   (The  ‘skip’  verb
       allows  you  to  experiment with test entries safely, or easily disable
       entries for hosts that are temporarily down.)


   Keyword/Option Summary
       Here are the legal options.  Keyword suffixes enclosed in square brack-
       ets are optional.  Those corresponding to command-line options are fol-
       lowed by ‘-’ and the appropriate option letter.

       Here are the legal global options:


       Keyword             Opt   Function
       -------------------------------------------------------------
       set daemon                Set a background poll interval  in
                                 seconds
       set postmaster            Give  the  name of the last-resort
                                 mail recipient
       set no bouncemail         Direct error  mail  to  postmaster
                                 rather than sender
       set no spambounce         Send spam bounces
       set logfile               Name  of  a file to dump error and
                                 status messages to
       set idfile                Name of  the  file  to  store  UID
                                 lists in
       set syslog                Do   error  logging  through  sys-
                                 log(3).
       set no syslog             Turn  off  error  logging  through
                                 syslog(3).
       set properties            String  value is ignored by fetch-
                                 mail (may  be  used  by  extension
                                 scripts)

       Here are the legal server options:


       Keyword            Opt   Function
       ------------------------------------------------------------
       via                      Specify  DNS  name  of mailserver,
                                overriding poll name
       proto[col]         -p    Specify  protocol  (case  insensi-
                                tive):  POP2,  POP3,  IMAP,  APOP,
                                KPOP
       local[domains]           Specify domain(s) to  be  regarded
                                as local
       port               -P    Specify TCP/IP service port
       auth[enticate]           Set  authentication  type (default
                                ‘any’)
       timeout            -t    Server inactivity timeout in  sec-
                                onds (default 300)
       envelope           -E    Specify   envelope-address  header
                                name
       no envelope              Disable   looking   for   envelope
                                address
       qvirtual           -Q    Qmail  virtual  domain  prefix  to
                                remove from user name
       aka                      Specify  alternate  DNS  names  of
                                mailserver
       interface          -I    specify  IP interface(s) that must
                                be up  for  server  poll  to  take
                                place
       monitor            -M    Specify  IP address to monitor for
                                activity
       plugin                   Specify command through  which  to
                                make server connections.
       plugout                  Specify  command  through which to
                                make listener connections.


       dns                      Enable DNS  lookup  for  multidrop
                                (default)
       no dns                   Disable DNS lookup for multidrop
       checkalias               Do  comparison  by  IP address for
                                multidrop
       no checkalias            Do comparison  by  name  for  mul-
                                tidrop (default)
       uidl               -U    Force   POP3  to  use  client-side
                                UIDLs
       no uidl                  Turn off POP3 use  of  client-side
                                UIDLs (default)
       interval                 Only  check this site every N poll
                                cycles; N is a numeric argument.
       tracepolls               Add poll  tracing  information  to
                                the Received header
       netsec                   Pass   in  IPsec  security  option
                                request.
       principal                Set Kerberos principal (only  use-
                                ful with imap and kerberos)
       esmtpname                Set  name  for RFC2554 authentica-
                                tion to the ESMTP server.
       esmtppassword            Set password for RFC2554 authenti-
                                cation to the ESMTP server.

       Here are the legal user options:


       Keyword            Opt   Function
       ------------------------------------------------------------
       user[name]         -u    Set  remote  user name (local user
                                name if name followed by ‘here’)
       is                       Connect  local  and  remote   user
                                names
       to                       Connect   local  and  remote  user
                                names
       pass[word]               Specify remote account password
       ssl                      Connect to server over the  speci-
                                fied   base   protocol  using  SSL
                                encryption
       sslcert                  Specify file for client side  pub-
                                lic SSL certificate
       sslkey                   Specify  file for client side pri-
                                vate SSL key
       sslproto                 Force ssl protocol for connection
       folder             -r    Specify remote folder to query
       smtphost           -S    Specify smtp host(s) to forward to
       fetchdomains             Specify  domains  for  which  mail
                                should be fetched
       smtpaddress        -D    Specify the domain to  be  put  in
                                RCPT TO lines
       smtpname                 Specify  the user and domain to be
                                put in RCPT TO lines
       antispam           -Z    Specify  what  SMTP  returns   are
                                interpreted as spam-policy blocks
       mda                -m    Specify MDA for local delivery
       bsmtp              -o    Specify BSMTP batch file to append
                                to
       preconnect               Command to be executed before each
                                connection
       postconnect              Command  to be executed after each
                                connection
       keep               -k    Don’t delete  seen  messages  from
                                server
       flush              -F    Flush  all  seen  messages  before
                                querying
       fetchall           -a    Fetch all messages whether seen or
                                not
       rewrite                  Rewrite  destination addresses for
                                reply (default)

       stripcr                  Strip carriage returns  from  ends
                                of lines
       forcecr                  Force  carriage returns at ends of
                                lines
       pass8bits                Force BODY=8BITMIME to ESMTP  lis-
                                tener
       dropstatus               Strip  Status and X-Mozilla-Status
                                lines out of incoming mail
       dropdelivered            Strip Delivered-To  lines  out  of
                                incoming mail
       mimedecode               Convert  quoted-printable to 8-bit
                                in MIME messages
       idle                     Idle  waiting  for  new   messages
                                after each poll (IMAP only)
       no keep            -K    Delete  seen  messages from server
                                (default)
       no flush                 Don’t  flush  all  seen   messages
                                before querying (default)
       no fetchall              Retrieve    only    new   messages
                                (default)
       no rewrite               Don’t rewrite headers
       no stripcr               Don’t   strip   carriage   returns
                                (default)
       no forcecr               Don’t  force  carriage  returns at
                                EOL (default)
       no pass8bits             Don’t force BODY=8BITMIME to ESMTP
                                listener (default)
       no dropstatus            Don’t    drop    Status    headers
                                (default)
       no dropdelivered         Don’t  drop  Delivered-To  headers
                                (default)
       no mimedecode            Don’t  convert quoted-printable to
                                8-bit in MIME messages (default)
       no idle                  Don’t idle waiting  for  new  mes-
                                sages after each poll (IMAP only)
       limit              -l    Set message size limit
       warnings           -w    Set message size warning interval
       batchlimit         -b    Max  # messages to forward in sin-
                                gle connect
       fetchlimit         -B    Max # messages to fetch in  single
                                connect
       fetchsizelimit           Max  #  message  sizes to fetch in
                                single transaction
       fastuidl                 Use binary search for first unseen
                                message (POP3 only)
       expunge            -e    Perform  an  expunge  on every #th
                                message (IMAP and POP3 only)
       properties               String value is ignored by  fetch-
                                mail  (may  be  used  by extension
                                scripts)

       Remember that all user options must follow all server options.

       In the .fetchmailrc file, the ‘envelope’ string argument  may  be  pre-
       ceded  by a whitespace-separated number.  This number, if specified, is
       the number of such headers to skip (that is, an argument of  1  selects
       the  second  header  of  the  given type).  This is sometime useful for
       ignoring bogus Received headers created  by  an  ISP’s  local  delivery
       agent.

   Keywords Not Corresponding To Option Switches
       The  ‘folder’ and ‘smtphost’ options (unlike their command-line equiva-
       lents) can take a space- or comma-separated  list  of  names  following
       them.

       All  options  correspond  to the obvious command-line arguments, except
       the following: ‘via’, ‘interval’, ‘aka’, ‘is’,  ‘to’,  ‘dns’/‘no  dns’,
       ‘checkalias’/‘no  checkalias’, ‘password’, ‘preconnect’, ‘postconnect’,
       ‘localdomains’,   ‘stripcr’/‘no   stripcr’,   ‘forcecr’/‘no   forcecr’,
       ‘pass8bits’/‘no       pass8bits’       ‘dropstatus/no      dropstatus’,
       ‘dropdelivered/no dropdelivered’, ‘mimedecode/no mimedecode’,  ‘idle/no
       idle’, and ‘no envelope’.

       The ‘via’ option is for if you want to have more than one configuration
       pointing at the same site.  If it is present, the string argument  will
       be  taken as the actual DNS name of the mailserver host to query.  This
       will override the argument of poll, which can then simply be a distinct
       label  for  the  configuration (e.g. what you would give on the command
       line to explicitly query this host).

       The ‘interval’ option (which takes a numeric argument)  allows  you  to
       poll a server less frequently than the basic poll interval.  If you say
       ‘interval N’ the server this option is attached to will only be queried
       every N poll intervals.

       The  ‘is’  or  ‘to’  keywords  associate  the  following local (client)
       name(s) (or server-name to client-name mappings separated  by  =)  with
       the mailserver user name in the entry.  If an is/to list has ‘*’ as its
       last name, unrecognized names are simply passed through.

       A single local name can be used to support redirecting your  mail  when
       your  username on the client machine is different from your name on the
       mailserver.  When there is only a single local name, mail is  forwarded
       to  that  local  username regardless of the message’s Received, To, Cc,
       and Bcc headers.  In this case fetchmail never does DNS lookups.

       When there is more than one local name (or name mapping) the  fetchmail
       code  does  look  at the Received, To, Cc, and Bcc headers of retrieved
       mail (this is ‘multidrop mode’).  It looks for addresses with  hostname
       parts  that match your poll name or your ‘via’, ‘aka’ or ‘localdomains’
       options, and usually also for hostname parts which  DNS  tells  it  are
       aliases  of the mailserver.  See the discussion of ‘dns’, ‘checkalias’,
       ‘localdomains’, and ‘aka’ for details on  how  matching  addresses  are
       handled.

       If  fetchmail  cannot  match  any  mailserver  usernames or localdomain
       addresses, the mail will be bounced.  Normally it will  be  bounced  to
       the sender, but if ‘nobounce’ is on it will go to the postmaster (which
       in turn defaults to being the calling user).

       The ‘dns’ option (normally on) controls the  way  addresses  from  mul-
       tidrop  mailboxes are checked.  On, it enables logic to check each host
       address that doesn’t match an ‘aka’ or  ‘localdomains’  declaration  by
       looking  it  up  with  DNS.   When  a mailserver username is recognized
       attached to a matching hostname part, its local mapping is added to the
       list of local recipients.

       The ‘checkalias’ option (normally off) extends the lookups performed by
       the ‘dns’ keyword in multidrop mode,  providing  a  way  to  cope  with
       remote  MTAs that identify themselves using their canonical name, while
       they’re polled using an alias.  When such a server is polled, checks to
       extract  the  envelope  address fail, and fetchmail reverts to delivery
       using  the  To/Cc/Bcc  headers  (See   below   ‘Header   vs.   Envelope
       addresses’).   Specifying  this  option instructs fetchmail to retrieve
       all the IP addresses associated with both the poll name  and  the  name
       used  by  the  remote  MTA  and to do a comparison of the IP addresses.
       This comes in handy in situations where  the  remote  server  undergoes
       frequent canonical name changes, that would otherwise require modifica-
       tions to the rcfile.  ‘checkalias’ has no effect if ‘no dns’ is  speci-
       fied in the rcfile.

       The ‘aka’ option is for use with multidrop mailboxes.  It allows you to
       pre-declare a list of DNS aliases for a server.  This is  an  optimiza-
       tion  hack  that  allows you to trade space for speed.  When fetchmail,
       while processing a multidrop mailbox, grovels through  message  headers
       looking for names of the mailserver, pre-declaring common ones can save
       it from having to do DNS lookups.  Note: the names you  give  as  argu-
       ments  to  ‘aka’  are  matched as suffixes -- if you specify (say) ‘aka
       netaxs.com’, this will match not just a hostnamed netaxs.com,  but  any
       hostname  that  ends  with ‘.netaxs.com’; such as (say) pop3.netaxs.com
       and mail.netaxs.com.

       The ‘localdomains’ option allows you to declare a list of domains which
       fetchmail  should  consider  local.   When fetchmail is parsing address
       lines in multidrop modes, and a trailing segment of a host name matches
       a declared local domain, that address is passed through to the listener
       or MDA unaltered (local-name mappings are not applied).

       If you are using ‘localdomains’, you may also need to specify ‘no enve-
       lope’,  which disables fetchmail’s normal attempt to deduce an envelope
       address from the Received line  or  X-Envelope-To  header  or  whatever
       header has been previously set by ‘envelope’.  If you set ‘no envelope’
       in the defaults entry it is possible to undo that in individual entries
       by using ‘envelope <string>’.  As a special case, ‘envelope "Received"’
       restores the default parsing of Received lines.

       The password option requires a string argument, which is  the  password
       to be used with the entry’s server.

       The  ‘preconnect’  keyword  allows you to specify a shell command to be
       executed just before each time fetchmail establishes a mailserver  con-
       nection.  This may be useful if you are attempting to set up secure POP
       connections with the aid of ssh(1).  If the command returns  a  nonzero
       status, the poll of that mailserver will be aborted.

       Similarly,  the ‘postconnect’ keyword similarly allows you to specify a
       shell command to be executed just after each time a mailserver  connec-
       tion is taken down.

       The  ‘forcecr’  option controls whether lines terminated by LF only are
       given CRLF termination before  forwarding.   Strictly  speaking  RFC821
       requires  this,  but few MTAs enforce the requirement it so this option
       is normally off (only one such MTA, qmail, is  in  significant  use  at
       time of writing).

       The ‘stripcr’ option controls whether carriage returns are stripped out
       of retrieved mail before it is forwarded.  It is normally not necessary
       to  set  this,  because it defaults to ‘on’ (CR stripping enabled) when
       there is an MDA declared but ‘off’ (CR stripping  disabled)  when  for-
       warding is via SMTP.  If ‘stripcr’ and ‘forcecr’ are both on, ‘stripcr’
       will override.

       The ‘pass8bits’ option exists to cope with Microsoft mail programs that
       stupidly  slap a "Content-Transfer-Encoding: 7bit" on everything.  With
       this option off (the default) and  such  a  header  present,  fetchmail
       declares  BODY=7BIT  to an ESMTP-capable listener; this causes problems
       for messages actually using 8-bit ISO or KOI-8  character  sets,  which
       will be garbled by having the high bits of all characters stripped.  If
       ‘pass8bits’ is on, fetchmail is forced to declare BODY=8BITMIME to  any
       ESMTP-capable  listener.   If  the  listener is 8-bit-clean (as all the
       major ones now are) the right thing will probably result.

       The ‘dropstatus’ option controls whether nonempty Status and X-Mozilla-
       Status  lines  are retained in fetched mail (the default) or discarded.
       Retaining them allows your MUA to  see  what  messages  (if  any)  were
       marked seen on the server.  On the other hand, it can confuse some new-
       mail notifiers, which assume that anything with a Status line in it has
       been  seen.   (Note:  the empty Status lines inserted by some buggy POP
       servers are unconditionally discarded.)

       The ‘dropdelivered’ option controls wether Delivered-To headers will be
       kept  in  fetched  mail  (the  default) or discarded. These headers are
       added by Qmail and Postfix mailservers in order to avoid mail loops but
       may get in your way if you try to "mirror" a mailserver within the same
       domain. Use with caution.

       The ‘mimedecode’  option  controls  whether  MIME  messages  using  the
       quoted-printable  encoding  are automatically converted into pure 8-bit
       data. If you are delivering mail to an ESMTP-capable, 8-bit-clean  lis-
       tener  (that  includes  all of the major MTAs like sendmail), then this
       will automatically convert quoted-printable message  headers  and  data
       into  8-bit  data, making it easier to understand when reading mail. If
       your e-mail programs know how to deal with  MIME  messages,  then  this
       option is not needed.  The mimedecode option is off by default, because
       doing RFC2047 conversion on headers throws away character-set  informa-
       tion and can lead to bad results if the encoding of the headers differs
       from the body encoding.

       The ‘idle’ option is intended to be used with IMAP  servers  supporting
       the  RFC2177  IDLE command extension, but does not strictly require it.
       If it is enabled, and fetchmail detects that IDLE is supported, an IDLE
       will be issued at the end of each poll.  This will tell the IMAP server
       to hold the connection open and notify the  client  when  new  mail  is
       available.   If  IDLE  is  not supported, fetchmail will simulate it by
       periodically issuing NOOP. If you need to poll a link frequently,  IDLE
       can  save  bandwidth  by  eliminating  TCP/IP connects and LOGIN/LOGOUT
       sequences. On the other hand, an IDLE connection will eat almost all of
       your  fetchmail’s  time,  because it will never drop the connection and
       allow other pools to occur unless the server times out  the  IDLE.   It
       also  doesn’t  work  with  multiple folders; only the first folder will
       ever be polled.


       The ‘properties’ option is an extension mechanism.  It takes  a  string
       argument,  which  is  ignored by fetchmail itself.  The string argument
       may be used  to  store  configuration  information  for  scripts  which
       require  it.   In  particular, the output of ‘--configdump’ option will
       make properties associated with a user entry  readily  available  to  a
       Python script.


   Miscellaneous Run Control Options
       The  words  ‘here’  and  ‘there’ have useful English-like significance.
       Normally ‘user eric is esr’ would mean that mail for  the  remote  user
       ‘eric’  is  to  be delivered to ‘esr’, but you can make this clearer by
       saying ‘user eric there is esr here’, or reverse it by saying ‘user esr
       here is eric there’

       Legal protocol identifiers for use with the ‘protocol’ keyword are:

           auto (or AUTO)
           pop2 (or POP2)
           pop3 (or POP3)
           sdps (or SDPS)
           imap (or IMAP)
           apop (or APOP)
           kpop (or KPOP)


       Legal  authentication  types  are ‘any’, ‘password’, ‘kerberos’, ’kere-
       beros_v5’ and ‘gssapi’, ‘cram-md5’, ‘otp’, ‘ntlm’, ‘ssh‘.   The  ‘pass-
       word’  type  specifies authentication by normal transmission of a pass-
       word (the password may be plaintext  or  subject  to  protocol-specific
       encryption as in APOP); ‘kerberos’ tells fetchmail to try to get a Ker-
       beros ticket at the start of each query instead, and send an  arbitrary
       string  as  the  password;  and  ‘gssapi’ tells fetchmail to use GSSAPI
       authentication.  See the description of the ‘auth’ keyword for more.

       Specifying ‘kpop’ sets POP3 protocol over port 1109  with  Kerberos  V4
       authentication.  These defaults may be overridden by later options.

       There  are  currently four global option statements; ‘set logfile’ fol-
       lowed by a string sets the same global specified by --logfile.  A  com-
       mand-line --logfile option will override this.  Also, ‘set daemon’ sets
       the poll interval as --daemon does.  This can be overridden by  a  com-
       mand-line  --daemon  option;  in  particular  --daemon 0 can be used to
       force foreground operation. The ‘set  postmaster’  statement  sets  the
       address to which multidrop mail defaults if there are no local matches.
       Finally, ‘set syslog’ sends log messages to syslogd(8).



INTERACTION WITH RFC 822

       When trying to determine the originating address of a  message,  fetch-
       mail looks through headers in the following order:

               Return-Path:
               Resent-Sender: (ignored if it doesn’t contain an @ or !)
               Sender: (ignored if it doesn’t contain an @ or !)
               Resent-From:
               From:
               Reply-To:
               Apparently-From:

       The  originating  address is used for logging, and to set the MAIL FROM
       address when forwarding to SMTP.  This order is intended to cope grace-
       fully  with  receiving  mailing  list  messages  in multidrop mode. The
       intent is that if a local address doesn’t  exist,  the  bounce  message
       won’t  be  returned  blindly  to  the author or to the list itself, but
       rather to the list manager (which is less annoying).

       In multidrop mode, destination headers are processed as follows: First,
       fetchmail looks for the Received: header (or whichever one is specified
       by the ‘envelope’ option) to determine the local recipient address.  If
       the  mail  is  addressed  to more than one recipient, the Received line
       won’t contain any information regarding recipient addresses.

       Then fetchmail looks for the Resent-To:,  Resent-Cc:,  and  Resent-Bcc:
       lines.   If  they  exists, they should contain the final recipients and
       have precedence over their To:/Cc:/Bcc: counterparts.  If the  Resent-*
       lines  doesn’t  exist,  the To:, Cc:, Bcc: and Apparently-To: lines are
       looked for. (The presence of a Resent-To: is taken to  imply  that  the
       person  referred  by  the To: address has already received the original
       copy of the mail).



CONFIGURATION EXAMPLES

       Note that although there are password declarations in a  good  many  of
       the  examples below, this is mainly for illustrative purposes.  We rec-
       ommend stashing account/password pairs in your $HOME/.netrc file, where
       they  can  be  used  not just by fetchmail but by ftp(1) and other pro-
       grams.

       Basic format is:

         poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD

       Example:

         poll pop.provider.net protocol pop3 username "jsmith" password "secret1"

       Or, using some abbreviations:

         poll pop.provider.net proto pop3 user "jsmith" password "secret1"

       Multiple servers may be listed:

         poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
         poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"

       Here’s a version of those two  with  more  whitespace  and  some  noise
       words:

         poll pop.provider.net proto pop3
             user "jsmith", with password secret1, is "jsmith" here;
         poll other.provider.net proto pop2:
             user "John.Smith", with password "My^Hat", is "John.Smith" here;

       This version is much easier to read and doesn’t cost significantly more
       (parsing is done only once, at startup time).


       If you need to include whitespace in a parameter  string,  enclose  the
       string in double quotes.  Thus:

         poll mail.provider.net with proto pop3:
               user "jsmith" there has password "u can’t krak this"
                           is jws here and wants mda "/bin/mail"

       You  may  have  an  initial  server  description  headed by the keyword
       ‘defaults’ instead of ‘poll’ followed by a  name.   Such  a  record  is
       interpreted  as  defaults for all queries to use. It may be overwritten
       by individual server descriptions.  So, you could write:

         defaults proto pop3
               user "jsmith"
         poll pop.provider.net
               pass "secret1"
         poll mail.provider.net
               user "jjsmith" there has password "secret2"

       It’s possible to specify more than one user per server  (this  is  only
       likely  to  be  useful  when running fetchmail in daemon mode as root).
       The ‘user’ keyword leads off a user description, and every user  speci-
       fication in a multi-user entry must include it.  Here’s an example:

         poll pop.provider.net proto pop3 port 3111
               user "jsmith" with pass "secret1" is "smith" here
               user jones with pass "secret2" is "jjones" here keep

       This  associates  the  local username ‘smith’ with the pop.provider.net
       username  ‘jsmith’  and  the   local   username   ‘jjones’   with   the
       pop.provider.net  username  ‘jones’.   Mail  for ‘jones’ is kept on the
       server after download.

       Here’s what a simple retrieval configuration for a  multi-drop  mailbox
       looks like:

         poll pop.provider.net:
               user maildrop with pass secret1 to golux ’hurkle’=’happy’ snark here

       This  says  that  the  mailbox of account ‘maildrop’ on the server is a
       multi-drop box, and that messages in it should be parsed for the server
       user  names  ‘golux’, ‘hurkle’, and ‘snark’.  It further specifies that
       ‘golux’ and ‘snark’ have the same name on the client as on the  server,
       but  mail  for  server user ‘hurkle’ should be delivered to client user
       ‘happy’.

       Here’s an example of another kind of multidrop connection:

         poll pop.provider.net localdomains loonytoons.org toons.org:
               user maildrop with pass secret1 to * here

       This also says that the mailbox of account ‘maildrop’ on the server  is
       a  multi-drop  box.   It tells fetchmail that any address in the loony-
       toons.org or toons.org  domains  (including  subdomain  addresses  like
       ‘joe@daffy.loonytoons.org’)  should be passed through to the local SMTP
       listener without modification.  Be careful of  mail  loops  if  you  do
       this!

       Here’s  an  example configuration using ssh and the plugin option.  The
       queries are made directly on the stdin and stdout  of  imapd  via  ssh.
       Note that in this setup, IMAP authentication can be skipped.

       poll mailhost.net with proto imap:
               plugin "ssh %h /usr/sbin/imapd" auth ssh;
                       user esr is esr here



THE USE AND ABUSE OF MULTIDROP MAILBOXES

       Use  the multiple-local-recipients feature with caution -- it can bite.
       All multidrop features are ineffective in ETRN and ODMR modes.

       Also, note that in multidrop mode duplicate mails  are  suppressed.   A
       piece  of mail is considered duplicate if it has the same message-ID as
       the message immediately preceding and more than  one  addressee.   Such
       runs of messages may be generated when copies of a message addressed to
       multiple users are delivered to a multidrop box.


   Header vs. Envelope addresses
       The fundamental problem is that by having your mailserver toss  several
       peoples’ mail in a single maildrop box, you may have thrown away poten-
       tially vital information about who each  piece  of  mail  was  actually
       addressed  to  (the  ‘envelope  address’,  as  opposed  to  the  header
       addresses in the RFC822 To/Cc/Bcc headers).  This ‘envelope address’ is
       the address you need in order to reroute mail properly.

       Sometimes fetchmail can deduce the envelope address.  If the mailserver
       MTA is sendmail and the item of mail had just one  recipient,  the  MTA
       will  have  written a ‘by/for’ clause that gives the envelope addressee
       into its Received header. But this  doesn’t  work  reliably  for  other
       MTAs,  nor  if there is more than one recipient.  By default, fetchmail
       looks for envelope addresses in  these  lines;  you  can  restore  this
       default with -E "Received" or ‘envelope Received’.

       Alternatively,  some SMTP listeners and/or mail servers insert a header
       in each message containing a copy  of  the  envelope  addresses.   This
       header  (when it exists) is often ‘X-Envelope-To’.  Fetchmail’s assump-
       tion about this can be changed with the -E or ‘envelope’ option.   Note
       that  writing  an  envelope  header  of  this kind exposes the names of
       recipients (including blind-copy recipients) to all  receivers  of  the
       messages;  it  is  therefore regarded by some administrators as a secu-
       rity/privacy problem.

       A slight variation of the ‘X-Envelope-To’ header is the  ‘Delivered-To’
       put by qmail to avoid mail loops. It will probably prefix the user name
       with a string that normally matches the user’s domain. To  remove  this
       prefix you can use the -Q or ‘qvirtual’ option.

       Sometimes,  unfortunately,  neither  of these methods works.  When they
       all fail, fetchmail must fall back on the contents of To/Cc/Bcc headers
       to try to determine recipient addressees -- and these are not reliable.
       In particular, mailing-list software often ships  mail  with  only  the
       list broadcast address in the To header.

       When fetchmail cannot deduce a recipient address that is local, and the
       intended recipient address was anyone other than  fetchmail’s  invoking
       user,  mail  will  get  lost.  This is what makes the multidrop feature
       risky.

       A related problem is that when you blind-copy a mail message,  the  Bcc
       information  is  carried  only as envelope address (it’s not put in the
       headers fetchmail can see unless there is an X-Envelope header).  Thus,
       blind-copying  to someone who gets mail over a fetchmail link will fail
       unless the the mailserver host routinely writes X-Envelope or an equiv-
       alent header into messages in your maildrop.


   Good Ways To Use Multidrop Mailboxes
       Multiple  local names can be used to administer a mailing list from the
       client side of a fetchmail collection.  Suppose your name is ‘esr’, and
       you  want  to  both  pick  up your own mail and maintain a mailing list
       called (say) "fetchmail-users", and you want to keep the alias list  on
       your client machine.

       On your server, you can alias ‘fetchmail-users’ to ‘esr’; then, in your
       .fetchmailrc, declare ‘to esr fetchmail-users here’.  Then,  when  mail
       including  ‘fetchmail-users’  as a local address gets fetched, the list
       name will be appended to the list  of  recipients  your  SMTP  listener
       sees.   Therefore  it will undergo alias expansion locally.  Be sure to
       include ‘esr’ in the  local  alias  expansion  of  fetchmail-users,  or
       you’ll  never  see  mail sent only to the list.  Also be sure that your
       listener has the "me-too"  option  set  (sendmail’s  -oXm  command-line
       option or OXm declaration) so your name isn’t removed from alias expan-
       sions in messages you send.

       This trick is not without its problems, however.  You’ll begin  to  see
       this  when  a message comes in that is addressed only to a mailing list
       you do not have declared as a local name.  Each such message will  fea-
       ture  an ‘X-Fetchmail-Warning’ header which is generated because fetch-
       mail cannot find a valid local name in the recipient  addresses.   Such
       messages  default  (as  was described above) to being sent to the local
       user running fetchmail, but the program has no way to know that  that’s
       actually the right thing.


   Bad Ways To Abuse Multidrop Mailboxes
       Multidrop mailboxes and fetchmail serving multiple users in daemon mode
       do not mix.  The problem, again, is mail from mailing lists, which typ-
       ically  does  not  have an individual recipient address on it.   Unless
       fetchmail can deduce an envelope address, such mail will only go to the
       account  running  fetchmail  (probably root).  Also, blind-copied users
       are very likely never to see their mail at all.

       If you’re tempted to use fetchmail to retrieve mail for multiple  users
       from  a  single  mail drop via POP or IMAP, think again (and reread the
       section on header and envelope addresses above).  It would  be  smarter
       to  just let the mail sit in the mailserver’s queue and use fetchmail’s
       ETRN or ODMR modes to trigger SMTP sends periodically (of course,  this
       means  you  have  to  poll more frequently than the mailserver’s expiry
       period).  If you can’t arrange this, try setting up a UUCP feed.

       If you absolutely must use multidrop for this purpose, make  sure  your
       mailserver  writes  an  envelope-address header that fetchmail can see.
       Otherwise you will lose mail and it will come back to haunt you.


   Speeding Up Multidrop Checking
       Normally, when multiple users are declared fetchmail extracts recipient
       addresses  as described above and checks each host part with DNS to see
       if it’s an alias of the mailserver.  If so, the name mappings described
       in the to ... here declaration are done and the mail locally delivered.

       This is the safest but also slowest  method.   To  speed  it  up,  pre-
       declare  mailserver  aliases  with  ‘aka’; these are checked before DNS
       lookups are done.  If you’re certain your aka  list  contains  all  DNS
       aliases  of  the  mailserver  (and all MX names pointing at it) you can
       declare ‘no dns’ to  suppress  DNS  lookups  entirely  and  only  match
       against the aka list.



EXIT CODES

       To  facilitate  the  use of fetchmail in shell scripts, an exit code is
       returned to give an indication of what occurred during a given  connec-
       tion.

       The exit codes returned by fetchmail are as follows:

       0      One  or more messages were successfully retrieved (or, if the -c
              option was selected, were found waiting but not retrieved).

       1      There was no mail awaiting retrieval.  (There may have been  old
              mail still on the server but not selected for retrieval.)

       2      An  error  was  encountered  when attempting to open a socket to
              retrieve mail.  If you don’t know what a socket is, don’t  worry
              about  it  -- just treat this as an ’unrecoverable error’.  This
              error can also be because a protocol fetchmail wants to  use  is
              not listed in /etc/services.

       3      The  user authentication step failed.  This usually means that a
              bad user-id, password, or APOP id was specified.  Or it may mean
              that you tried to run fetchmail under circumstances where it did
              not have standard input attached to a  terminal  and  could  not
              prompt for a missing password.

       4      Some sort of fatal protocol error was detected.

       5      There was a syntax error in the arguments to fetchmail.

       6      The run control file had bad permissions.

       7      There  was  an error condition reported by the server.  Can also
              fire if fetchmail timed out while waiting for the server.

       8      Client-side exclusion error.  This means fetchmail either  found
              another  copy of itself already running, or failed in such a way
              that it isn’t sure whether another copy is running.

       9      The user authentication step failed because the server responded
              "lock  busy".  Try again after a brief pause!  This error is not
              implemented for all protocols, nor  for  all  servers.   If  not
              implemented  for  your server, "3" will be returned instead, see
              above.  May be returned when talking to qpopper or other servers
              that  can respond with "lock busy" or some similar text contain-
              ing the word "lock".

       10     The fetchmail run failed while trying to do an SMTP port open or
              transaction.

       11     Fatal  DNS error.  Fetchmail encountered an error while perform-
              ing a DNS lookup at startup and could not proceed.

       12     BSMTP batch file could not be opened.

       13     Poll terminated by a fetch limit (see the --fetchlimit  option).

       14     Server busy indication.

       15     Server timed out during an IMAP IDLE.

       23     Internal error.  You should see a message on standard error with
              details.

       When fetchmail queries more than one host, return status is  0  if  any
       query  successfully retrieved mail. Otherwise the returned error status
       is that of the last host queried.



FILES

       ~/.fetchmailrc
            default run control file

       ~/.fetchids
            default location of file associating hosts with last  message  IDs
            seen (used only with newer RFC1725-compliant POP3 servers support-
            ing the UIDL command).

       ~/.fetchmail.pid
            lock file to help prevent concurrent runs (non-root mode).

       ~/.netrc
            your FTP run control file, which (if present) will be searched for
            passwords as a last resort before prompting for one interactively.

       /var/run/fetchmail.pid
            lock file to help prevent concurrent runs (root mode,  Linux  sys-
            tems).

       /etc/fetchmail.pid
            lock  file  to  help  prevent  concurrent runs (root mode, systems
            without /var/run).



ENVIRONMENT

       If the FETCHMAILUSER variable is set, it is used as  the  name  of  the
       calling  user  (default  local name) for purposes such as mailing error
       notifications.  Otherwise, if either the LOGNAME or  USER  variable  is
       correctly  set (e.g. the corresponding UID matches the session user ID)
       then that name is used as the  default  local  name.   Otherwise  getp-
       wuid(3)  must  be  able to retrieve a password entry for the session ID
       (this elaborate logic is designed to handle the case of multiple  names
       per userid gracefully).

       If  the environment variable FETCHMAILHOME is set to a valid and exist-
       ing directory name, the .fetchmailrc and .fetchids  and  .fetchmail.pid
       files  are  put  there instead of in the invoking user’s home directory
       (and lose the leading dots on their names).  The .netrc file is  looked
       for  in the the invoking user’s home directory regardless of FETCHMAIL-
       HOME’s setting.



SIGNALS

       If a fetchmail daemon is running as root, SIGHUP wakes it up  from  its
       sleep  phase  and  forces a poll of all non-skipped servers (this is in
       accordance with the usual conventions for system daemons).

       If fetchmail is running in daemon mode as non-root, use SIGUSR1 to wake
       it  (this  is  so SIGHUP due to logout can retain the default action of
       killing it).

       Running fetchmail in foreground while a background fetchmail is running
       will do whichever of these is appropriate to wake it up.



BUGS AND KNOWN PROBLEMS

       The  mda  and plugin options interact badly.  In order to collect error
       status from the MDA, fetchmail has to change its normal signal handling
       so  that  dead  plugin  processes don’t get reaped until the end of the
       poll cycle.  This can cause resource starvation  if  too  many  zombies
       accumulate.   So  either  don’t  deliver to a MDA using plugins or risk
       being overrun by an army of undead.

       The RFC822 address  parser  used  in  multidrop  mode  chokes  on  some
       @-addresses  that  are  technically legal but bizarre.  Strange uses of
       quoting and embedded comments are likely to confuse it.

       In a message with multiple envelope headers, only  the  last  one  pro-
       cessed  will  be  visible  to  fetchmail.   To  get  around this, use a
       mailserver-side filter that consolidates the contents of  all  envelope
       headers into a single one (procmail, mailagent, or maildrop can be pro-
       grammed to do this fairly easily).

       Use of some of these protocols requires that  the  program  send  unen-
       crypted  passwords  over the TCP/IP connection to the mailserver.  This
       creates a risk that name/password pairs might be snaffled with a packet
       sniffer  or  more  sophisticated  monitoring software.  Under Linux and
       FreeBSD, the --interface option can be  used  to  restrict  polling  to
       availability  of  a  specific interface device with a specific local or
       remote IP address, but snooping is still possible if  (a)  either  host
       has a network device that can be opened in promiscuous mode, or (b) the
       intervening network link can be tapped.  We recommend the use of ssh(1)
       tunnelling  to  not  only  shroud your passwords but encrypt the entire
       conversation.

       Use of the %F or %T escapes in an mda  option  could  open  a  security
       hole, because they pass text manipulable by an attacker to a shell com-
       mand.  Potential shell characters are replaced by ‘_’ before execution.
       The hole is further reduced by the fact that fetchmail temporarily dis-
       cards any suid privileges it may have while running the MDA.  For maxi-
       mum  safety, however, don’t use an mda command containing %F or %T when
       fetchmail is run from the root account itself.

       Fetchmail’s method of sending bouncemail and spam bounces requires that
       port 25 of localhost be available for sending mail via SMTP.

       If  you  modify a ~/.fetchmailrc while a background instance is running
       and break the  syntax,  the  background  instance  will  die  silently.
       Unfortunately,  it  can’t die noisily because we don’t yet know whether
       syslog should be enabled.  On some systems, fetchmail dies quietly even
       if  there  is  no syntax error; this seems to have something to do with
       buggy terminal ioctl code in the kernel.

       The -f - option (reading a configuration from  stdin)  is  incompatible
       with the plugin option.

       The  UIDL code is generally flaky and tends to lose its state on errors
       and line drops (so that old messages are re-seen).  If this happens  to
       you, switch to IMAP4.

       The ‘principal’ option only handles Kerberos IV, not V.

       Send comments, bug reports, gripes, and the like to the fetchmail-users
       list <fetchmail-users@lists.berlios.de>.  An HTML FAQ is  available  at
       the  fetchmail  home  page; surf to http://fetchmail.berlios.de or do a
       WWW search for pages with ‘fetchmail’ in their titles.



AUTHOR

       Eric S. Raymond <esr@snark.thyrsus.com>.  Too many other people to name
       here have contributed code and patches.  This program is descended from
       and replaces popclient, by Carl Harris <ceharris@mal.com>;  the  inter-
       nals  have  become quite different, but some of its interface design is
       directly traceable to that ancestral program.



SEE ALSO

       mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)


APPLICABLE STANDARDS

       SMTP/ESMTP:
            RFC 821, RFC2821, RFC 1869, RFC 1652,  RFC  1870,  RFC  1983,  RFC
            1985, RFC 2554.

       mail:
            RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.

       POP2:
            RFC 937

       POP3:
            RFC  1081,  RFC  1225,  RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC
            1957, RFC2195, RFC 2449.

       APOP:
            RFC 1460, RFC 1725, RFC 1939.

       RPOP:
            RFC 1081, RFC 1225.

       IMAP2/IMAP2BIS:
            RFC 1176, RFC 1732.

       IMAP4/IMAP4rev1:
            RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061,  RFC  2195,  RFC
            2177, RFC 2683.

       ETRN:
            RFC 1985.

       ODMR/ATRN:
            RFC 2645.

       OTP: RFC 1938.

       LMTP:
            RFC 2033.

       GSSAPI:
            RFC 1508.

       TLS  RFC 2595.




                                                                  fetchmail(1)

Man(1) output converted with man2html