2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Man page for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
9 fetchmail \- fetch mail from a POP, IMAP, or ETRN-capable server
12 \fBfetchmail\fR [\fIoptions\fR] [\fImailserver...\fR]
18 is a mail-retrieval and forwarding utility; it fetches
19 mail from remote mailservers and forwards it to your local (client)
20 machine's delivery system. You can then handle the retrieved mail
21 using normal mail user agents such as \fIelm\fR(1) or \fIMail\fR(1).
22 The \fBfetchmail\fR utility can be run in a daemon mode to repeatedly
23 poll one or more systems at a specified interval.
27 program can gather mail from servers supporting any of the common
28 mail-retrieval protocols: POP2, POP3, IMAP2bis, and IMAP4. It can
29 also use the ESMTP ETRN extension. (The RFCs describing all these
30 protocols are listed at the end of this document.)
34 is primarily intended to be used over on-demand TCP/IP links (such as
35 SLIP or PPP connections), it may also be useful as a message transfer
36 agent for sites which refuse for security reasons to permit
37 (sender-initiated) SMTP transactions with sendmail.
39 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
40 port 25 on the machine it is running on (localhost), just as though it
41 were being passed in over a normal TCP/IP link. The mail will then be
42 delivered locally via your system's MDA (Mail Delivery Agent, usually
43 \fIsendmail\fR(8) but your system may use a different one such
44 as \fIsmail\fR, \fImmdf\fR, or \fIqmail\fR). All the delivery-control
45 mechanisms (such as \fI.forward\fR files) normally available through
46 your system MDA and local delivery agents will therefore work.
50 is available, it will assist you in setting up and editing a
51 fetchmailrc configuration. It runs under X and requires that the
52 language Python and the Tk toolkit be present on your system. If
53 you are first setting up fetchmail for single-user mode, it is
54 recommended that you use Novice mode. Expert mode provides
55 complete control of fetchmail configuration, including the
56 multidrop features. In either case, the `Autoprobe' button
57 will tell you the most capable protocol a given mailserver
58 supported, and warn you of potential problems with that server.
63 is controlled by command-line options and a run control file,
64 .IR ~/.fetchmailrc\fR ,
65 the syntax of which we describe in a later section (this file is what
66 the \fIfetchmailconf\fR program edits). Command-line options override
70 Each server name that you specify following the options on the
71 command line will be queried. If you don't specify any servers
72 on the command line, each server in your
76 To facilitate the use of
78 In scripts, pipelines, etc., it returns an appropriate exit code upon
79 termination -- see EXIT CODES below.
80 The following options modify the behavior of \fIfetchmail\fR. It is
81 seldom necessary to specify any of these once you have a
82 working \fI.fetchmailrc\fR file set up.
84 Almost all options have a corresponding keyword which can be used to
89 Some special options are not covered here, but are documented instead
90 in sections on AUTHENTICATION and DAEMON MODE which follow.
94 Displays the version information for your copy of
96 No mail fetch is performed.
97 Instead, for each server specified, all option information
98 that would be computed if
100 were connecting to that server is displayed. Any non-printables in
101 passwords or other string names are shown as backslashed C-like
102 escape sequences. This option is useful for verifying that your
103 options are set the way you want them.
106 Return a status code to indicate whether there is mail waiting,
107 without actually fetching or deleting mail (see EXIT CODES below).
108 This option turns off daemon mode (in which it would be useless). It
109 doesn't play well with queries to multiple sites, and doesn't work
110 with ETRN. It will return a false positive if you leave read but
111 undeleted mail in your server mailbox and your fetch protocol can't
112 tell kept messages from new ones. This means it will work with IMAP,
113 not work with POP2, and may occasionally flake out under POP3.
116 Silent mode. Suppresses all progress/status messages that are
117 normally echoed to standard error during a fetch (but does not
118 suppress actual error messages). The --verbose option overrides this.
121 Verbose mode. All control messages passed between
123 and the mailserver are echoed to stderr. Overrides --silent.
124 Doubling this option (-v -v) causes extra diagnostic information
130 Retrieve both old (seen) and new messages from the mailserver. The
131 default is to fetch only messages the server has not marked seen.
132 Under POP3, this option also forces the use of RETR rather than TOP.
133 Note that POP2 retrieval behaves as though --all is always on (see
134 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN.
138 Keep retrieved messages on the remote mailserver. Normally, messages
139 are deleted from the folder on the mailserver after they have been retrieved.
142 option causes retrieved messages to remain in your folder on the
143 mailserver. This option does not work with ETRN.
147 Delete retrieved messages from the remote mailserver. This
148 option forces retrieved mail to be deleted. It may be useful if
149 you have specified a default of \fBkeep\fR in your
150 \&\fI.fetchmailrc\fR. This option is forced on with ETRN.
153 POP3/IMAP only. Delete old (previously retrieved) messages from the mailserver
154 before retrieving new messages. This option does not work with ETRN.
155 Warning: if your local MTA hangs and fetchmail is aborted, the next
156 time you run fetchmail, it will delete mail that was never delivered to you.
157 What you probably want is the default setting: if you don't specify `-k', then
158 fetchmail will automatically delete messages after successful delivery.
159 .SS Protocol and Query Options
161 .B \-p, \--protocol proto
162 (Keyword: proto[col])
163 Specify the protocol to use when communicating with the remote
164 mailserver. If no protocol is specified, the default is AUTO.
166 may be one of the following:
169 Tries each of the supported protocols in turn, terminating after
170 any successful attempt.
172 Post Office Protocol 2
174 Post Office Protocol 3
176 Use POP3 with MD5 authentication.
178 Use POP3 with RPOP authentication.
180 Use POP3 with Kerberos V4 authentication on port 1109.
182 Use POP3 with Demon Internet's SDPS extensions.
184 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
186 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
187 with RFC 1731 Kerberos v4 authentication.
189 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
190 with RFC 1731 GSSAPI authentication.
192 Use the ESMTP ETRN option.
194 All these alternatives work in basically the same way (communicating
195 with standard server daemons to fetch mail already delivered to a
196 mailbox on the server) except ETRN. The ETRN mode allows you to ask a
197 compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
198 higher) to immediately open a sender-SMTP connection to your
199 client machine and begin forwarding any items addressed to your client
200 machine in the server's queue of undelivered mail.
204 Force UIDL use (effective only with POP3). Force client-side tracking
205 of `newness' of messages (UIDL stands for ``unique ID listing'' and is
206 described in RFC1725). Use with `keep' to use a mailbox as a baby
207 news drop for a group of users.
211 The port option permits you to specify a TCP/IP port to connect on.
212 This option will seldom be necessary as all the supported protocols have
213 well-established default port numbers.
217 The timeout option allows you to set a server-nonresponse
218 timeout in seconds. If a mailserver does not send a greeting message
219 or respond to commands for the given number of seconds,
220 \fIfetchmail\fR will hang up on it. Without such a timeout
221 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
222 down host. This would be particularly annoying for a \fIfetchmail\fR
223 running in background. There is a default timeout which fetchmail -V
228 The plugin option allows you to use an external program to establish the
229 TCP connection. This is useful if you want to use socks or need some
230 special firewalling setup. The program will be looked up in $PATH and
231 it will be passed two arguments: the name of the server and the name of
236 Identical to the plugin option above, but this one is used for the SMTP
237 connections (which will probably not need it, so it has been separated
240 .B \-r folder, --folder folder
242 Causes a specified non-default mail folder on the mailserver (or
243 comma-separated list of folders) to be retrieved. The syntax of the
244 folder name is server-dependent. This option is not available under
246 .SS Delivery Control Options
248 .B \-S hosts, --smtphost hosts
249 (Keyword: smtp[host])
250 Specify a hunt list of hosts to forward mail to (one or more
251 hostnames, comma-separated). In ETRN mode, set the host that the
252 mailserver is asked to ship mail to. Hosts are tried in list order;
253 the first one that is up becomes the forwarding or ETRN target for the
254 current run. Normally, `localhost' is added to the end of the list as
255 an invisible default. However, when using ETRN mode or Kerberos
256 authentication, the FQDN of the machine running fetchmail is added to
257 the end of the list as an invisible default. Each hostname may have a
258 '/'-delimited suffix specifying a port or service to forward to; the
259 default is 25 (or "smtp" under IPv6).
261 .B \-D domain, --smtpaddress domain
262 (Keyword: smtpaddress)
263 Specify the domain to be put in RCPT TO lines shipped to SMTP. The
264 name of the SMTP server (as specified by --smtphost, or defaulted to
265 "localhost") is used when this is not specified.
267 .B \-Z nnn, --antispam nnn[,nnn[,nnn...]]
269 Specifies the list of numeric SMTP errors that are to be interpreted
270 as a spam-block response from the listener. A value of -1 disables
271 this option. For the command-line option, the list values should
276 You can force mail to be passed to an MDA directly (rather than
277 forwarded to port 25) with the -mda or -m option. If \fIfetchmail\fR
278 is running as root, it sets its userid to that of the target user
279 while delivering mail through an MDA. Some possible MDAs are
280 "/usr/sbin/sendmail -oem $USER", "/usr/bin/procmail -d $USER"
281 and "/usr/bin/deliver". Local delivery addresses
282 will be inserted into the MDA command wherever you place a %T; the
283 mail message's From address will be inserted where you place an %F. Do
284 \fInot\fR use an MDA invocation like
285 "sendmail -oem -t" that dispatches on the contents of To/Cc/Bcc, it
286 will create mail loops and bring the just wrath of many postmasters
291 Cause delivery via LMTP (Local Mail Transfer Protocol). A service port
292 \fdImust\fR be explicitly specified if this option is selected; port
293 25 will (in accordance with RFC 2033) not be accepted.
297 Append fetched mail to a BSMTP file. This simply contains the SMTP
298 commands that would normally be generated by fetchmail when passing
299 mail to an SMTP listener daemon. An argument of `-' causes the mail
300 to be written to standard output. Note that fetchmail's
301 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
302 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
303 MAILBOXES below apply.
304 .SS Resource Limit Control Options
308 Takes a maximum octet size argument. Messages larger than this size
309 will not be fetched, not be marked seen, and will be left on the
310 server (in foreground sessions, the progress messages will note that
311 they are "oversized"). An explicit --limit of 0 overrides any limits
312 set in your run control file. This option is intended for those
313 needing to strictly control fetch time due to expensive and variable
314 phone rates. In daemon mode, oversize notifications are mailed to the
315 calling user (see the --warnings option). This option does not work
320 Takes an interval in seconds. When you call
322 with a `limit' option in daemon mode, this controls the interval at
323 which warnings about oversized messages are mailed to the calling user
324 (or the user specified by the `postmaster' option). One such
325 notification is always mailed at the end of the the first poll that
326 the oversized message is detected. Thereafter, renotification is
327 suppressed until after the warning interval elapses (it will take
328 place at the end of the first following poll).
331 (Keyword: batchlimit)
332 Specify the maximum number of messages that will be shipped to an SMTP
333 listener before the connection is deliberately torn down and rebuilt
334 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
335 overrides any limits set in your run control file. While
336 \fBsendmail\fR(8) normally initiates delivery of a message immediately
337 after receiving the message terminator, some SMTP listeners are not so
338 prompt. MTAs like \fIqmail\fR(8) and \fIsmail\fR(8) may wait till the
339 delivery socket is shut down to deliver. This may produce annoying
342 is processing very large batches. Setting the batch limit to some
343 nonzero size will prevent these delays.
344 This option does not work with ETRN.
347 (Keyword: fetchlimit)
348 Limit the number of messages accepted from a given server in a single
349 poll. By default there is no limit. An explicit --fetchlimit of 0
350 overrides any limits set in your run control file.
351 This option does not work with ETRN.
355 When talking to an IMAP server,
357 normally issues an EXPUNGE command after each deletion in order to
358 force the deletion to be done immediately. This is safest when your
359 connection to the server is flaky and expensive, as it avoids
360 resending duplicate mail after a line hit. However, on large
361 mailboxes the overhead of re-indexing after every message can slam the
362 server pretty hard, so if your connection is reliable it is good to do
363 expunges less frequently. If you specify this option to an integer N,
366 to only issue expunges on every Nth delete. An argument
367 of zero suppresses expunges entirely (so no expunges at all will be
368 done until the end of run).
369 This option does not work with ETRN, POP2, or POP3.
370 .SS Authentication Options
372 .B \-u name, --username name
373 (Keyword: user[name])
374 Specifies the user identification to be used when logging in to the mailserver.
375 The appropriate user identification is both server and user-dependent.
376 The default is your login name on the client machine that is running
378 See USER AUTHENTICATION below for a complete description.
380 .B \-I specification, --interface specification
382 Require that a specific interface device be up and have a specific local
383 IP address (or range) before polling. Frequently
385 is used over a transient point-to-point TCP/IP link established directly
386 to a mailserver via SLIP or PPP. That is a relatively secure channel.
387 But when other TCP/IP routes to the mailserver exist (e.g. when the link
388 is connected to an alternate ISP), your username and password may be
389 vulnerable to snooping (especially when daemon mode automatically polls
390 for mail, shipping a clear password over the net at predictable
391 intervals). The --interface option may be used to prevent this. When
392 the specified link is not up or is not connected to a matching IP
393 address, polling will be skipped. The format is:
395 interface/iii.iii.iii.iii/mmm.mmm.mmm.mmm
397 The field before the first slash is the interface name (i.e. sl0, ppp0
398 etc.). The field before the second slash is the acceptable IP address.
399 The field after the second slash is a mask which specifies a range of
400 IP addresses to accept. If no mask is present 255.255.255.255 is
401 assumed (i.e. an exact match). This option is currently only supported
404 .B \-M interface, --monitor interface
406 Daemon mode can cause transient links which are automatically taken down
407 after a period of inactivity (e.g. PPP links) to remain up
408 indefinitely. This option identifies a system TCP/IP interface to be
409 monitored for activity. After each poll interval, if the link is up but
410 no other activity has occurred on the link, then the poll will be
411 skipped. This option is currently only supported under Linux.
414 (Keyword: auth[enticate])
415 This option permits you to specify a preauthentication type (see USER
416 AUTHENTICATION below for details). The possible values are
417 \&`\fBpassword\fR', `\fBkerberos_v5\fR' and `\fBkerberos\fR' (or, for
418 excruciating exactness, `\fBkerberos_v4\fR'). This option is provided
419 primarily for developers; choosing KPOP protocol automatically selects
420 Kerberos preauthentication, and all other alternatives use password
421 authentication (though APOP uses a generated one-time key as the
422 password and IMAP-K4 uses RFC1731 Kerberos v4 authentication). This
423 option does not work with ETRN.
424 .SS Miscellaneous Options
426 .B \-f pathname, --fetchmailrc pathname
427 Specify a non-default name for the
429 run control file. The pathname argument must be either "-" (a single
430 dash, meaning to read the configuration from standard input) or a
431 filename. Unless the --version option is also on, a named file
432 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
435 .B \-i pathname, --idfile pathname
437 Specify an alternate name for the .fetchids file used to save POP3
441 (Keyword: no rewrite)
444 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
445 fetched mail so that any mail IDs local to the server are expanded to
446 full addresses (@ and the mailserver hostname are appended). This enables
447 replies on the client to get addressed correctly (otherwise your
448 mailer might think they should be addressed to local users on the
449 client machine!). This option disables the rewrite. (This option is
450 provided to pacify people who are paranoid about having an MTA edit
451 mail headers and want to know they can prevent it, but it is generally
452 not a good idea to actually turn off rewrite.)
453 When using ETRN, the rewrite option is ineffective.
457 This option changes the header
459 assumes will carry a copy of the mail's envelope address. Normally
460 this is `X-Envelope-To' but as this header is not standard, practice
461 varies. See the discussion of multidrop address handling below. As a
462 special case, `envelope "Received"' enables parsing of sendmail-style
463 Received lines. This is the default, and it should not be necessary
464 unless you have globally disabled Received parsing with `no envelope'
465 in the \fI.fetchmailrc\fR file.
469 The string prefix assigned to this option will be removed from the user
470 name found in the header specified with the \fIenvelope\fR option
471 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
472 if either is applicable). This option is useful if you are using
474 to collect the mail for an entire domain and your ISP (or your mail
475 redirection provider) is using qmail.
476 One of the basic features of qmail is the
480 message header. Whenever qmail delivers a message to a local mailbox
481 it puts the username and hostname of the envelope recipient on this
482 line. The major reason for this is to prevent mail loops. To set up
483 qmail to batch mail for a disconnected site the ISP-mailhost will have
484 normally put that site in its `Virtualhosts' control file so it will
485 add a prefix to all mail addresses for this site. This results in mail
486 sent to 'username@userhost.userdom.dom.com' having a
487 \&`Delivered-To:' line of the form:
489 Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
491 The ISP can make the 'mbox-userstr-' prefix anything they choose
492 but a string matching the user host name is likely.
493 By using the option `envelope Delivered-To:' you can make fetchmail reliably
494 identify the original envelope recipient, but you have to strip the
495 `mbox-userstr-' prefix to deliver to the correct user.
496 This is what this option is for.
501 file, interpret any command-line options specified, and dump a
502 configuration report to standard output. The configuration report is
503 a data structure assignment in the language Python. This option
504 is meant to be used with an interactive
506 editor written in Python.
508 .SH USER AUTHENTICATION AND ENCRYPTION
509 Every mode except ETRN requires authentication of the client.
510 Normal user authentication in
512 is very much like the authentication mechanism of
514 The correct user-id and password depend upon the underlying security
515 system at the mailserver.
517 If the mailserver is a Unix machine on which you have an ordinary user
518 account, your regular login name and password are used with
520 If you use the same login name on both the server and the client machines,
521 you needn't worry about specifying a user-id with the
524 the default behavior is to use your login name on the client machine as the
525 user-id on the server machine. If you use a different login name
526 on the server machine, specify that login name with the
528 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
533 fetchmail -u jsmith mailgrunt
535 The default behavior of
537 is to prompt you for your mailserver password before the connection is
538 established. This is the safest way to use
540 and ensures that your password will not be compromised. You may also specify
541 your password in your
543 file. This is convenient when using
545 in daemon mode or with scripts.
547 If you do not specify a password, and
549 cannot extract one from your
551 file, it will look for a
553 file in your home directory before requesting one interactively; if an
554 entry matching the mailserver is found in that file, the password will
557 man page for details of the syntax of the
559 file. (This feature may allow you to avoid duplicating password
560 information in more than one file.)
562 On mailservers that do not provide ordinary user accounts, your user-id and
563 password are usually assigned by the server administrator when you apply for
564 a mailbox on the server. Contact your server administrator if you don't know
565 the correct user-id and password for your mailbox account.
567 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
568 independent authentication using the
570 file on the mailserver side. Under this RPOP variant, a fixed
571 per-user ID equivalent to a password was sent in clear over a link to
572 a reserved port, with the command RPOP rather than PASS to alert the
573 server that it should do special checking. RPOP is supported
576 (you can specify `protocol RPOP' to have the program send `RPOP'
577 rather than `PASS') but its use is strongly discouraged. This
578 facility was vulnerable to spoofing and was withdrawn in RFC1460.
580 RFC1460 introduced APOP authentication. In this variant of POP3,
581 you register an APOP password on your server host (the program
582 to do this with on the server is probably called \fIpopauth\fR(8)). You
583 put the same password in your
587 logs in, it sends a cryptographically secure hash of your password and
588 the server greeting time to the server, which can verify it by
589 checking its authorization database.
591 If your \fIfetchmail\fR was built with Kerberos support and you specify
592 Kerberos preauthentication (either with --auth or the \fI.fetchmailrc\fR
593 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
594 ticket from the mailserver at the start of each query. Note: if
595 either the pollnane or via name is `hesiod', fetchmail will try to use
596 Hesiod to look up the mailserver.
598 If you use IMAP-K4, \fIfetchmail\fR will expect the IMAP server to have
599 RFC1731-conformant AUTHENTICATE KERBEROS_V4 capability, and will use it.
601 If you use IMAP-GSS, \fIfetchmail\fR will expect the IMAP server to have
602 RFC1731-conformant AUTHENTICATE GSSAPI capability, and will use it.
603 Currently this has only been tested over Kerberos V, so you're expected
604 to already have a ticket-granting ticket. You may pass a username different
605 from your principal name using the standard \fB--user\fR command or by
606 the \fI.fetchmailrc\fR option \fBuser\fR.
608 If you are using POP3, and the server issues a one-time-password
609 challenge conforming to RFC1938, \fIfetchmail\fR will use your
610 password as a pass phrase to generate the required response. This
611 avoids sending secrets over the net unencrypted.
613 Compuserve's RPA authentication (similar to APOP) is supported. If
614 you are using POP3, and the RPA code has been compiled into your
615 binary, and you query a server in the Compuserve csi.com domain,
616 \fIfetchmail\fR will try to perform an RPA pass-phrase authentication
617 instead of sending over the password en clair.
619 If you are using IPsec, the -T (--netsec) option can be used to pass
620 an IP security request to be used when outgoing IP connections are
621 initialized. You can also do this using the `netsec' server option
622 in the .fetchmailrc file. In either case, the option value is a
623 string in the format accepted by the net_security_strtorequest()
624 function of the inet6_apps library.
633 in daemon mode. You must specify a numeric argument which is a
634 polling interval in seconds.
638 puts itself in background and runs forever, querying each specified
639 host and then sleeping for the given polling interval.
645 will, therefore, poll all the hosts described in your
647 file (except those explicitly excluded with the `skip' verb) once
648 every fifteen minutes.
650 It is possible to set a polling interval
653 file by saying `set daemon <interval>', where <interval> is an
654 integer number of seconds. If you do this, fetchmail will always
655 start in daemon mode unless you override it with the command-line
656 option --daemon 0 or -d0.
658 Only one daemon process is permitted per user; in daemon mode,
660 makes a per-user lockfile to guarantee this.
662 Normally, calling fetchmail with a daemon in the background sends a
663 wakeup signal to the daemon, forcing it to poll mailservers
664 immediately. (The wakeup signal is SIGHUP if fetchmail is running as
665 root, SIGUSR1 otherwise.)
669 will kill a running daemon process instead of waking it up (if there
672 notifies you). If the --quit option is the only command-line option,
673 that's all there is to it.
675 The quit option may also be mixed with other command-line options; its
676 effect is to kill any running daemon before doing what the other
677 options specify in combination with the rc file.
683 option (keyword: set logfile) allows you to redirect status messages
684 emitted while detached into a specified logfile (follow the
685 option with the logfile name). The logfile is opened for append, so
686 previous messages aren't deleted. This is primarily useful for
687 debugging configurations.
691 option (keyword: set syslog) allows you to redirect status and error
692 messages emitted to the
694 system daemon if available.
695 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
696 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
697 This option is intended for logging status and error messages which
698 indicate the status of the daemon and the results while fetching mail
700 Error messages for command line options and parsing the \fI.fetchmailrc\fR
701 file are still written to stderr, or the specified log file if the
704 option turns off use of
706 assuming it's turned on in the
716 or --nodetach option suppresses backgrounding and detachment of the
717 daemon process from its control terminal. This is primarily useful
718 for debugging. Note that this also causes the logfile option to be
719 ignored (though perhaps it shouldn't).
721 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
722 transient errors (such as DNS failures or sendmail delivery refusals)
723 may force the fetchall option on for the duration of the next polling
724 cycle. This is a robustness feature. It means that if a message is
725 fetched (and thus marked seen by the mailserver) but not delivered
726 locally due to some transient error, it will be re-fetched during the
727 next poll cycle. (The IMAP logic doesn't delete messages until
728 they're delivered, so this problem does not arise.)
730 .SH ADMINISTRATIVE OPTIONS
734 option (keyword: set postmaster) specifies the last-resort username to
735 which multidrop mail is to be forwarded if no matching local recipient
736 can be found. Normally this is just the user who invoked fetchmail.
737 If the invoking user is root, then the default of this option is
738 the user `postmaster'.
742 option (keyword: set invisible) tries to make fetchmail invisible.
743 Normally, fetchmail behaves like any other MTA would -- it generates a
744 Received header into each message describing its place in the chain of
745 transmission, and tells the MTA it forwards to that the mail came from
746 the machine fetchmail itself is running on. If the invisible option
747 is on, the Received header is suppressed and fetchmail tries to spoof
748 the MTA it forwards to into thinking it came directly from the
751 .SH RETRIEVAL FAILURE MODES
752 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
753 bulletproof. In normal operation forwarding to port 25, no message is
754 ever deleted (or even marked for deletion) on the host until the SMTP
755 listener on the client has acknowledged to \fIfetchmail\fR that the
756 message has been accepted for delivery. When forwarding to an MDA,
757 however, there is more possibility of error (because there's no way
758 for fetchmail to get a reliable positive acknowledgement from the MDA).
760 The normal mode of \fIfetchmail\fR is to try to download only `new'
761 messages, leaving untouched (and undeleted) messages you have already
762 read directly on the server (or fetched with a previous \fIfetchmail
763 --keep\fR). But you may find that messages you've already read on the
764 server are being fetched (and deleted) even when you don't specify
765 --all. There are several reasons this can happen.
767 One could be that you're using POP2. The POP2 protocol includes no
768 representation of `new' or `old' state in messages, so \fIfetchmail\fR
769 must treat all messages as new all the time. But POP2 is obsolete, so
772 Under POP3, blame RFC1725. That version of the POP3 protocol
773 specification removed the LAST command, and some POP servers follow it
774 (you can verify this by invoking \fIfetchmail -v\fR to the mailserver
775 and watching the response to LAST early in the query). The
776 \fIfetchmail\fR code tries to compensate by using POP3's UID feature,
777 storing the identifiers of messages seen in each session until the
778 next session, in the \fI.fetchids\fR file. But this doesn't track
779 messages seen with other clients, or read directly with a mailer on
780 the host but not deleted afterward. A better solution would be to
783 Another potential POP3 problem might be servers that insert messages
784 in the middle of mailboxes (some VMS implementations of mail are
785 rumored to do this). The \fIfetchmail\fR code assumes that new
786 messages are appended to the end of the mailbox; when this is not true
787 it may treat some old messages as new and vice versa. The only
788 real fix for this problem is to switch to IMAP.
790 The IMAP code uses the presence or absence of the server flag \eSeen
791 to decide whether or not a message is new. Under Unix, it counts on
792 your IMAP server to notice the BSD-style Status flags set by mail user
793 agents and set the \eSeen flag from them when appropriate. All Unix
794 IMAP servers we know of do this, though it's not specified by the IMAP
795 RFCs. If you ever trip over a server that doesn't, the symptom will
796 be that messages you have already read on your host will look new to
797 the server. In this (unlikely) case, only messages you fetched with
798 \fIfetchmail --keep\fR will be both undeleted and marked old.
800 In ETRN mode, \fIfetchmail\fR does not actually retrieve messages;
801 instead, it asks the server's SMTP listener to start a queue flush
802 to the client via SMTP. Therefore it sends only undelivered messages.
805 Many SMTP listeners allow administrators to set up `spam filters' that
806 block unsolicited email from specified domains. A MAIL FROM line that
807 triggers this feature will elicit an SMTP response which
808 (unfortunately) varies according to the listener.
812 return an error code of 571. This return value
813 is blessed by RFC1893 as "Delivery not authorized, message refused".
815 According to current drafts of the replacement for RFC821, the correct
816 thing to return in this situation is 550 "Requested action not taken:
817 mailbox unavailable" (the draft adds "[E.g., mailbox not found, no
818 access, or command rejected for policy reasons].").
822 MTA returns 501 "Syntax error in parameters or arguments", but will
827 code recognizes and discards the message on any of a list of responses
828 that defaults to [571, 550, 501] but can be set with the `antispam'
831 circumstance under which fetchmail ever discards mail.
835 is fetching from an IMAP server, the antispam response will be detected and
836 the message rejected immediately after the headers have been fetched,
837 without reading the message body. Thus, you won't pay for downloading
840 .SH THE RUN CONTROL FILE
841 The preferred way to set up fetchmail is to write a
842 \&\fI.fetchmailrc\fR file in your home directory (you may do this
843 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
844 When there is a conflict between the command-line arguments and the
845 arguments in this file, the command-line arguments take precedence.
847 To protect the security of your passwords, when --version is not on
848 your \fI~/.fetchmailrc\fR may not have more than 0600 (u=rw,g=,o=) permissions;
850 will complain and exit otherwise.
852 You may read the \fI.fetchmailrc\fR file as a list of commands to
855 is called with no arguments.
856 .SS Run Control Syntax
858 Comments begin with a '#' and extend through the end of the line.
859 Otherwise the file consists of a series of server entries or global
860 option statements in a free-format, token-oriented syntax.
862 There are four kinds of tokens: grammar keywords, numbers
863 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
864 A quoted string is bounded by double quotes and may contain
865 whitespace (and quoted digits are treated as a string). An unquoted
866 string is any whitespace-delimited token that is neither numeric, string
867 quoted nor contains the special characters `,', `;', `:', or `='.
869 Any amount of whitespace separates tokens in server entries, but is
870 otherwise ignored. You may use standard C-style escapes (\en, \et,
871 \eb, octal, and hex) to embed non-printable characters or string
872 delimiters in strings.
874 Each server entry consists of one of the keywords `poll' or `skip',
875 followed by a server name, followed by server options, followed by any
876 number of user descriptions. Note: the most common cause of syntax
877 errors is mixing up user and server options.
879 For backward compatibility, the word `server' is a synonym for `poll'.
881 You can use the noise keywords `and', `with',
882 \&`has', `wants', and `options' anywhere in an entry to make
883 it resemble English. They're ignored, but but can make entries much
884 easier to read at a glance. The punctuation characters ':', ';' and
885 \&',' are also ignored.
888 The `poll' verb tells fetchmail to query this host when it is run with
889 no arguments. The `skip' verb tells
891 not to poll this host unless it is explicitly named on the command
892 line. (The `skip' verb allows you to experiment with test entries
893 safely, or easily disable entries for hosts that are temporarily down.)
895 .SS Keyword/Option Summary
896 Here are the legal options. Keyword suffixes enclosed in
897 square brackets are optional. Those corresponding to command-line
898 options are followed by `-' and the appropriate option letter.
900 Here are the legal global options:
907 Set a background poll interval in seconds
910 Give the name of the last-resort mail recipient
913 Name of a file to dump error and status messages to
916 Name of the file to store UID lists in
919 Do error logging through syslog(3).
922 Turn off error logging through syslog(3).
926 Here are the legal server options:
933 Specify DNS name of mailserver, overriding poll name
936 Specify protocol (case insensitive):
937 POP2, POP3, IMAP, IMAP-K4, IMAP-GSS, APOP, KPOP
940 Specify TCP/IP service port
943 Set preauthentication type (default `password')
946 Server inactivity timeout in seconds (default 300)
949 Specify envelope-address header name
952 Disable looking for envelope address
955 Qmail virtual domain prefix to remove from user name
958 Specify alternate DNS names of mailserver
961 specify IP interface(s) that must be up for server poll to take place
964 Specify IP address to monitor for activity
967 Specify command through which to make server connections.
970 Specify command through which to make listener connections.
973 Enable DNS lookup for multidrop (default)
976 Disable DNS lookup for multidrop
979 Do comparison by IP address for multidrop
982 Do comparison by name for multidrop (default)
985 Force POP3 to use client-side UIDLs
988 Turn off POP3 use of client-side UIDLs (default)
992 Here are the legal user options:
1000 (local user name if name followed by `here')
1003 Connect local and remote user names
1006 Connect local and remote user names
1009 Specify remote account password
1012 Specify remote folder to query
1015 Specify smtp host(s) to forward to
1018 Specify the domain to be put in RCPT TO lines
1021 Specify what SMTP returns are interpreted as spam-policy blocks
1024 Specify MDA for local delivery
1027 Specify BSMTP batch file to append to
1030 Command to be executed before each connection
1033 Command to be executed after each connection
1036 Don't delete seen messages from server
1039 Flush all seen messages before querying
1042 Fetch all messages whether seen or not
1045 Rewrite destination addresses for reply (default)
1048 Strip carriage returns from ends of lines
1051 Force carriage returns at ends of lines
1054 Force BODY=8BITMIME to ESMTP listener
1057 Strip Status and X-Mozilla-Status lines out of incoming mail
1060 Convert quoted-printable to 8-bit in MIME messages
1063 Delete seen messages from server (default)
1066 Don't flush all seen messages before querying (default)
1069 Retrieve only new messages (default)
1072 Don't rewrite headers
1075 Don't strip carriage returns (default)
1078 Don't force carriage returns at EOL (default)
1081 Don't force BODY=8BITMIME to ESMTP listener (default)
1084 Don't drop Status headers (default)
1087 Don't convert quoted-printable to 8-bit in MIME messages (default)
1090 Set message size limit
1093 Set message size warning interval
1096 Max # messages to fetch in single connect
1099 Max # messages to forward in single connect
1102 Perform an expunge on every #th message (IMAP only)
1105 String value is ignored by fetchmail (may be used by extension scripts)
1109 Remember that all user options must \fIfollow\fR all server options.
1111 In the .fetchmailrc file, the `envelope' string argument may be
1112 preceded by a whitespace-separated number. This number, if specified,
1113 is the number of such headers to skip (that is, an argument of 1
1114 selects the second header of the given type). This is sometime useful
1115 for ignoring bogus Received headers created by an ISP's local delivery
1117 .SS Keywords Not Corresponding To Option Switches
1119 The `folder' and `smtphost' options (unlike their command-line
1120 equivalents) can take a space- or comma-separated list of names
1123 All options correspond to the obvious command-line arguments, except
1124 the following: `via', `interval', `aka', `is', `to', `dns'/`no dns',
1125 `checkalias'/`no checkalias', `password', `preconnect', `postconnect',
1126 `localdomains', `stripcr'/`no stripcr', `forcecr'/`no forcecr',
1127 `pass8bits'/`no pass8bits' `dropstatus/no dropstatus', `mimedecode/no
1128 mimedecode', and `no envelope'.
1130 The `via' option is for use with ssh, or if you want to have more
1131 than one configuration pointing at the same site. If it is present,
1132 the string argument will be taken as the actual DNS name of the
1133 mailserver host to query.
1134 This will override the argument of poll, which can then simply be a
1135 distinct label for the configuration (e.g. what you would give on the
1136 command line to explicitly query this host).
1137 If the `via' name is `localhost', the poll name will also still be
1138 used as a possible match in multidrop mode; otherwise the `via' name
1139 will be used instead and the poll name will be purely a label.
1141 The `interval' option (which takes a numeric argument) allows you to poll a
1142 server less frequently than the basic poll interval. If you say
1143 \&`interval N' the server this option is attached to will only be
1144 queried every N poll intervals.
1146 The `is' or `to' keywords associate the following local (client)
1147 name(s) (or server-name to client-name mappings separated by =) with
1148 the mailserver user name in the entry. If an is/to list has `*' as
1149 its last name, unrecognized names are simply passed through.
1151 A single local name can be used to support redirecting your mail when
1152 your username on the client machine is different from your name on the
1153 mailserver. When there is only a single local name, mail is forwarded
1154 to that local username regardless of the message's Received, To, Cc,
1155 and Bcc headers. In this case
1157 never does DNS lookups.
1159 When there is more than one local name (or name mapping) the
1160 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1161 headers of retrieved mail (this is `multidrop mode'). It looks for
1162 addresses with hostname parts that match your poll name or your `via',
1163 `aka' or `localdomains' options, and usually also for hostname parts
1164 which DNS tells it are aliases of the mailserver. See the discussion
1165 of `dns', `checkalias', `localdomains', and `aka' for details on how
1166 matching addresses are handled.
1168 If \fIfetchmail\fR cannot match any mailserver usernames or
1169 localdomain addresses, the default recipient is the value of the
1170 `postmaster' global option if that has been set; otherwise it's the
1171 calling user (as set by the USER or LOGNAME variable in the
1174 The `dns' option (normally on) controls the way addresses from
1175 multidrop mailboxes are checked. On, it enables logic to check each
1176 host address that doesn't match an `aka' or `localdomains' declaration
1177 by looking it up with DNS. When a mailserver username is recognized
1178 attached to a matching hostname part, its local mapping is added to
1179 the list of local recipients.
1181 The `checkalias' option (normally off) extends the lookups performed
1182 by the `dns' keyword in multidrop mode, providing a way to cope with
1183 remote MTAs that identify themselves using their canonical name, while
1184 they're polled using an alias.
1185 When such a server is polled, checks to extract the envelope address
1188 reverts to delivery using the To/Cc/Bcc headers (See below
1189 `Header vs. Envelope addresses').
1190 Specifying this option instructs
1192 to retrieve all the IP addresses associated with both the poll name
1193 and the name used by the remote MTA and to do a comparison of the IP
1194 addresses. This comes in handy in situations where the remote server
1195 undergoes frequent canonical name changes, that would otherwise
1196 require modifications to the rcfile. `checkalias' has no effect if
1197 `no dns' is specified in the rcfile.
1199 The `aka' option is for use with multidrop mailboxes. It allows you
1200 to pre-declare a list of DNS aliases for a server. This is an
1201 optimization hack that allows you to trade space for speed. When
1203 while processing a multidrop mailbox, grovels through message headers
1204 looking for names of the mailserver, pre-declaring common ones can
1205 save it from having to do DNS lookups.
1207 The `localdomains' option allows you to declare a list of domains
1208 which fetchmail should consider local. When fetchmail is parsing
1209 address lines in multidrop modes, and a trailing segment of a host
1210 name matches a declared local domain, that address is passed through
1211 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1214 If you are using `localdomains', you may also need to specify \&`no
1215 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1216 an envelope address from the Received line or X-Envelope-To header or
1217 whatever header has been previously set by `envelope'. If you set `no
1218 envelope' in the defaults entry it is possible to undo that in
1219 individual entries by using `envelope <string>'. As a special case,
1220 \&`envelope "Received"' restores the default parsing of
1223 The \fBpassword\fR option requires a string argument, which is the password
1224 to be used with the entry's server.
1226 The `preconnect' keyword allows you to specify a shell command to be
1227 executed just before each time
1229 establishes a mailserver connection. This may be useful if you are
1230 attempting to set up secure POP connections with the aid of
1232 If the command returns a nonzero status, the poll of that mailserver
1235 Similarly, the `postconnect' keyword similarly allows you to specify a
1236 shell command to be executed just after each time a mailserver
1237 connection is taken down.
1239 The `forcecr' option controls whether lines terminated by LF only are
1240 given CRLF termination before forwarding. Strictly speaking RFC821
1241 requires this, but few MTAs enforce the requirement it so this option
1242 is normally off (only one such MTA, qmail, is in significant use at
1245 The `stripcr' option controls whether carriage returns are stripped
1246 out of retrieved mail before it is forwarded. It is normally not
1247 necessary to set this, because it defaults to `on' (CR stripping
1248 enabled) when there is an MDA declared but `off' (CR stripping
1249 disabled) when forwarding is via SMTP. If `stripcr' and `forcecr' are
1250 both on, `stripcr' will override.
1252 The `pass8bits' option exists to cope with Microsoft mail programs that
1253 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1254 this option off (the default) and such a header present,
1256 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1257 messages actually using 8-bit ISO or KOI-8 character sets, which will
1258 be garbled by having the high bits of all characters stripped. If
1259 \&`pass8bits' is on,
1261 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1262 the listener is 8-bit-clean (as all the major ones now are) the right
1263 thing will probably result.
1265 The `dropstatus' option controls whether nonempty Status and
1266 X-Mozilla-Status lines are retained in fetched mail (the default) or
1267 discarded. Retaining them allows your MUA to see what messages (if
1268 any) were marked seen on the server. On the other hand, it can
1269 confuse some new-mail notifiers, which assume that anything with a
1270 Status line in it has been seen. (Note: the empty Status lines
1271 inserted by some buggy POP servers are unconditionally discarded.)
1273 The `mimedecode' option controls whether MIME messages using the
1274 quoted-printable encoding are automatically converted into pure
1275 8-bit data. If you are delivering mail to an ESMTP-capable,
1276 8-bit-clean listener (that includes all of the major programs
1277 like sendmail), then this will automatically convert quoted-printable
1278 message headers and data into 8-bit data, making it easier to
1279 understand when reading mail. If your e-mail programs know how to
1280 deal with MIME messages, then this option is not needed.
1282 The `properties' option is an extension mechanism. It takes a string
1283 argument, which is ignored by fetchmail itself. The string argument may be
1284 used to store configuration information for scripts which require it.
1285 In particular, the output of `--configdump' option will make properties
1286 associated with a user entry readily available to a Python script.
1288 .SS Miscellaneous Run Control Options
1289 The words `here' and `there' have useful English-like
1290 significance. Normally `user eric is esr' would mean that
1291 mail for the remote user `eric' is to be delivered to `esr',
1292 but you can make this clearer by saying `user eric there is esr here',
1293 or reverse it by saying `user esr here is eric there'
1295 Legal protocol identifiers for use with the `protocol' keyword are:
1302 imap-k4 (or IMAP-K4)
1303 imap-gss (or IMAP-GSS)
1308 Legal authentication types are `password' or `kerberos'. The former
1309 specifies authentication by normal transmission of a password (the
1310 password may be plaintext or subject to protocol-specific encryption
1311 as in APOP); the second tells \fIfetchmail\fR to try to get a Kerberos
1312 ticket at the start of each query instead, and send an arbitrary
1313 string as the password.
1315 Specifying `kpop' sets POP3 protocol over port 1109 with Kerberos V4
1316 preauthentication. These defaults may be overridden by later options.
1318 There are currently three global option statements; `set logfile'
1319 followed by a string sets the same global specified by --logfile. A
1320 command-line --logfile option will override this. Also, `set daemon'
1321 sets the poll interval as --daemon does. This can be overridden by
1322 a command-line --daemon option; in particular --daemon 0 can be used
1323 to force foreground operation. Finally, `set syslog' sends log
1324 messages to syslogd(8).
1326 .SH INTERACTION WITH RFC 822
1327 When trying to determine the originating address of a message,
1328 fetchmail looks through headers in the following order:
1338 The originating address is used for logging, and to set the MAIL FROM
1339 address when forwarding to SMTP. This order is intended to cope
1340 gracefully with receiving mailing list messages in multidrop mode. The
1341 intent is that if a local address doesn't exist, the bounce message
1342 won't be returned blindly to the author or to the list itself, but
1343 rather to the list manager (which is less annoying).
1345 In multidrop mode, destination headers are processed as follows:
1346 First, fetchmail looks for the Received: header (or whichever one is
1347 specified by the `envelope' option) to determine the local
1348 recipient address. If the mail is addressed to more than one recipient,
1349 the Received line won't contain any information regarding recipient addresses.
1351 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1352 lines. If they exists, they should contain the final recipients and
1353 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1354 lines doesn't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1355 looked for. (The presence of a Resent-To: is taken to imply that the
1356 person referred by the To: address has already received the original
1359 .SH CONFIGURATION EXAMPLES
1363 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1369 poll pop.provider.net protocol pop3 username jsmith password secret1
1372 Or, using some abbreviations:
1375 poll pop.provider.net proto pop3 user jsmith password secret1
1378 Multiple servers may be listed:
1381 poll pop.provider.net proto pop3 user jsmith pass secret1
1382 poll other.provider.net proto pop2 user John.Smith pass My^Hat
1385 Here's a version of those two with more whitespace and some noise words:
1388 poll pop.provider.net proto pop3
1389 user jsmith, with password secret1, is jsmith here;
1390 poll other.provider.net proto pop2:
1391 user John.Smith, with password My^Hat, is John.Smith here;
1394 This version is much easier to read and doesn't cost significantly
1395 more (parsing is done only once, at startup time).
1398 If you need to include whitespace in a parameter string, enclose the
1399 string in double quotes. Thus:
1402 poll mail.provider.net with proto pop3:
1403 user jsmith there has password "u can't krak this"
1404 is jws here and wants mda "/bin/mail"
1407 You may have an initial server description headed by the keyword
1408 `defaults' instead of `poll' followed by a name. Such a record
1409 is interpreted as defaults for all queries to use. It may be overwritten
1410 by individual server descriptions. So, you could write:
1415 poll pop.provider.net
1417 poll mail.provider.net
1418 user jjsmith there has password secret2
1421 It's possible to specify more than one user per server (this is only
1422 likely to be useful when running fetchmail in daemon mode as root).
1423 The `user' keyword leads off a user description, and every user specification
1424 in a multi-user entry must include it. Here's an example:
1427 poll pop.provider.net proto pop3 port 3111
1428 user jsmith with pass secret1 is smith here
1429 user jones with pass secret2 is jjones here
1432 This associates the local username `smith' with the pop.provider.net
1433 username `jsmith' and the local username `jjones' with the
1434 pop.provider.net username `jones'.
1436 Here's what a simple retrieval configuration for a multi-drop mailbox
1440 poll pop.provider.net:
1441 user maildrop with pass secret1 to golux hurkle=happy snark here
1444 This says that the mailbox of account `maildrop' on the server is a
1445 multi-drop box, and that messages in it should be parsed for the
1446 server user names `golux', `hurkle', and `snark'. It further
1447 specifies that `golux' and `snark' have the same name on the
1448 client as on the server, but mail for server user `hurkle' should be
1449 delivered to client user `happy'.
1451 Here's an example of another kind of multidrop connection:
1454 poll pop.provider.net localdomains loonytoons.org toons.org:
1455 user maildrop with pass secret1 to esr * here
1458 This also says that the mailbox of account `maildrop' on the server is
1459 a multi-drop box. It tells fetchmail that any address in the
1460 loonytoons.org or toons.org domains (including subdomain addresses like
1461 `joe@daffy.loonytoons.org') should be passed through to the local SMTP
1462 listener without modification. Be careful of mail loops if you do this!
1464 Here's an example configuration using ssh. The queries go through an
1465 ssh connecting local port 1234 to port 110 on mailhost.net; the
1466 preconnect command sets up the ssh.
1469 poll mailhost.net via localhost port 1234 with proto pop3:
1470 preconnect "ssh -f -L 1234:mailhost.net:110
1471 mailhost.net sleep 20 </dev/null >/dev/null";
1474 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
1475 Use the multiple-local-recipients feature with caution -- it can bite.
1476 Also note that all multidrop features are ineffective in ETRN mode.
1478 .SS Header vs. Envelope addresses
1479 The fundamental problem is that by having your mailserver toss several
1480 peoples' mail in a single maildrop box, you may have thrown away
1481 potentially vital information about who each piece of mail was
1482 actually addressed to (the `envelope address', as opposed to the
1483 header addresses in the RFC822 To/Cc/Bcc headers). This `envelope
1484 address' is the address you need in order to reroute mail properly.
1488 can deduce the envelope address. If the mailserver MTA is
1490 and the item of mail had just one recipient, the MTA will have written
1491 a `by/for' clause that gives the envelope addressee into its Received
1492 header. But this doesn't work reliably for other MTAs, nor if there is
1493 more than one recipient. By default, \fIfetchmail\fR looks for
1494 envelope addresses in these lines; you can restore this default with
1495 -E "Received" or \&`envelope Received'.
1497 Alternatively, some SMTP listeners and/or mail servers insert a header
1498 in each message containing a copy of the envelope addresses. This
1499 header (when it exists) is often `X-Envelope-To'. Fetchmail's
1500 assumption about this can be changed with the -E or `envelope' option.
1501 Note that writing an envelope header of this kind exposes the names of
1502 recipients (including blind-copy recipients) to all receivers of the
1503 messages; it is therefore regarded by some administrators as a
1504 security/privacy problem.
1506 A slight variation of the `X-Envelope-To' header is the `Delivered-To' put
1507 by qmail to avoid mail loops. It will probably prefix the user name with a
1508 string that normally matches the user's domain. To remove this prefix you
1509 can use the -Q or `qvirtual' option.
1511 Sometimes, unfortunately, neither of these methods works. When they
1512 all fail, fetchmail must fall back on the contents of To/Cc/Bcc
1513 headers to try to determine recipient addressees -- and these are not
1514 reliable. In particular, mailing-list software often ships mail with
1515 only the list broadcast address in the To header.
1519 cannot deduce a recipient address that is local, and the intended
1520 recipient address was anyone other than fetchmail's invoking user,
1521 mail will get lost. This is what makes the multidrop feature risky.
1523 A related problem is that when you blind-copy a mail message, the Bcc
1524 information is carried \fIonly\fR as envelope address (it's not put
1525 in the headers fetchmail can see unless there is an X-Envelope
1526 header). Thus, blind-copying to someone who gets mail over a
1527 fetchmail link will fail unless the the mailserver host routinely
1528 writes X-Envelope or an equivalent header into messages in your maildrop.
1530 .SS Good Ways To Use Multidrop Mailboxes
1531 Multiple local names can be used to administer a mailing list from the
1532 client side of a \fIfetchmail\fR collection. Suppose your name is
1533 \&`esr', and you want to both pick up your own mail and maintain a mailing
1534 list called (say) "fetchmail-friends", and you want to keep the alias
1535 list on your client machine.
1537 On your server, you can alias \&`fetchmail-friends' to `esr'; then, in
1538 your \fI.fetchmailrc\fR, declare \&`to esr fetchmail-friends here'.
1539 Then, when mail including `fetchmail-friends' as a local address
1540 gets fetched, the list name will be appended to the list of
1541 recipients your SMTP listener sees. Therefore it will undergo alias
1542 expansion locally. Be sure to include `esr' in the local alias
1543 expansion of fetchmail-friends, or you'll never see mail sent only to
1544 the list. Also be sure that your listener has the "me-too" option set
1545 (sendmail's -oXm command-line option or OXm declaration) so your name
1546 isn't removed from alias expansions in messages you send.
1548 This trick is not without its problems, however. You'll begin to see
1549 this when a message comes in that is addressed only to a mailing list
1550 you do \fInot\fR have declared as a local name. Each such message
1551 will feature an `X-Fetchmail-Warning' header which is generated
1552 because fetchmail cannot find a valid local name in the recipient
1553 addresses. Such messages default (as was described above) to being
1554 sent to the local user running
1556 but the program has no way to know that that's actually the right thing.
1558 .SS Bad Ways To Abuse Multidrop Mailboxes
1559 Multidrop mailboxes and
1561 serving multiple users in daemon mode do not mix. The problem, again, is
1562 mail from mailing lists, which typically does not have an individual
1563 recipient address on it. Unless
1565 can deduce an envelope address, such mail will only go to the account
1566 running fetchmail (probably root). Also, blind-copied users are very
1567 likely never to see their mail at all.
1569 If you're tempted to use
1571 to retrieve mail for multiple users from a single mail drop via POP or
1572 IMAP, think again (and reread the section on header and envelope
1573 addresses above). It would be smarter to just let the mail sit in the
1574 mailserver's queue and use fetchmail's ETRN mode to trigger SMTP sends
1575 periodically (of course, this means you have to poll more frequently
1576 than the mailserver's expiry period). If you can't arrange this, try
1577 setting up a UUCP feed.
1579 If you absolutely \fImust\fR use multidrop for this purpose, make sure
1580 your mailserver writes an envelope-address header that fetchmail can
1581 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
1584 .SS Speeding Up Multidrop Checking
1585 Normally, when multiple user are declared
1587 extracts recipient addresses as described above and checks each host
1588 part with DNS to see if it's an alias of the mailserver. If so, the
1589 name mappings described in the to ... here declaration are done and
1590 the mail locally delivered.
1592 This is the safest but also slowest method. To speed it up,
1593 pre-declare mailserver aliases with `aka'; these are checked before
1594 DNS lookups are done. If you're certain your aka list contains
1596 DNS aliases of the mailserver (and all MX names pointing at it)
1597 you can declare `no dns' to suppress DNS lookups entirely and
1598 \fIonly\fR match against the aka list.
1601 To facilitate the use of
1603 in shell scripts, an exit code is returned to give an indication
1604 of what occurred during a given connection.
1606 The exit codes returned by
1610 One or more messages were successfully retrieved.
1612 There was no mail awaiting retrieval. (There may have been old mail still
1613 on the server but not selected for retrieval.)
1615 An error was encountered when attempting to open a socket to retrieve
1616 mail. If you don't know what a socket is, don't worry about it --
1617 just treat this as an 'unrecoverable error'.
1619 The user authentication step failed. This usually means that a bad
1620 user-id, password, or APOP id was specified.
1622 Some sort of fatal protocol error was detected.
1624 There was a syntax error in the arguments to
1627 The run control file had bad permissions.
1629 There was an error condition reported by the server. Can also
1632 timed out while waiting for the server.
1634 Client-side exclusion error. This means
1636 either found another copy of itself already running, or failed in such
1637 a way that it isn't sure whether another copy is running.
1639 The user authentication step failed because the server responded "lock
1640 busy". Try again after a brief pause! This error is not implemented
1641 for all protocols, nor for all servers. If not implemented for your
1642 server, "3" will be returned instead, see above. May be returned when
1643 talking to qpopper or other servers that can respond with "lock busy"
1644 or some similar text containing the word "lock".
1648 run failed while trying to do an SMTP port open or transaction.
1650 Fatal DNS error. Fetchmail encountered an error while performing
1651 a DNS lookup at startup and could not proceed.
1653 BSMTP batch file could not be opened.
1655 Internal error. You should see a message on standard error with
1660 queries more than one host, return status is 0 if \fIany\fR query
1661 successfully retrieved mail. Otherwise the returned error status is
1662 that of the last host queried.
1665 Eric S. Raymond <esr@snark.thyrsus.com>.
1666 This program is descended from and replaces
1668 by Carl Harris <ceharris@mal.com>; the internals are quite different,
1669 but some of its interface design is directly traceable to that
1675 default run control file
1678 default location of file associating hosts with last message IDs seen
1679 (used only with newer RFC1725-compliant POP3 servers supporting the
1683 your FTP run control file, which (if present) will be searched for
1684 passwords as a last resort before prompting for one interactively.
1687 lock file to help prevent concurrent runs (non-root mode).
1689 /var/run/fetchmail.pid
1690 lock file to help prevent concurrent runs (root mode, Linux systems).
1693 lock file to help prevent concurrent runs (root mode, systems without /var/run).
1696 For correct initialization,
1698 requires either that both the USER and HOME environment variables are
1699 correctly set, or that \fBgetpwuid\fR(3) be able to retrieve a password
1700 entry from your user ID.
1705 daemon is running as root, SIGHUP wakes it up from its sleep phase and
1706 forces a poll of all non-skipped servers (this is in accordance with
1707 the usual conventions for system daemons).
1711 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
1712 so SIGHUP due to logout can retain the default action of killing it).
1716 in foreground while a background fetchmail is running will do
1717 whichever of these is appropriate to wake it up.
1719 .SH BUGS AND KNOWN PROBLEMS
1720 Enabling the `mimedecode' option (which defaults to off) may render
1721 invalid any PGP signatures attached to mail with quoted-printable headers.
1722 This bug will be fixed in a future version.
1724 The RFC822 address parser used in multidrop mode chokes on some
1725 @-addresses that are technically legal but bizarre. Strange uses of
1726 quoting and embedded comments are likely to confuse it.
1728 Use of any of the supported protocols other than POP3 with OTP or RPA, APOP,
1729 KPOP, IMAP-K4, IMAP-GSS, or ETRN requires that the program send unencrypted
1730 passwords over the TCP/IP connection to the mailserver. This creates
1731 a risk that name/password pairs might be snaffled with a packet
1732 sniffer or more sophisticated monitoring software. Under Linux, the
1733 --interface option can be used to restrict polling to availability of
1734 a specific interface device with a specific local IP address, but
1735 snooping is still possible if (a) either host has a network device
1736 that can be opened in promiscuous mode, or (b) the intervening network
1739 Use of the %F or %T escapes in an mda option could open a security
1740 hole, because they pass text manipulable by an attacker to a shell
1741 command. Potential shell characters are replaced by `_' before
1742 execution. The hole is further reduced by the fact that fetchmail
1743 temporarily discards any suid privileges it may have while running the
1744 MDA. For maximum safety, however, don't use an mda command containing
1745 %F or %T when fetchmail is run from the root account itself.
1747 LMTP support is untested. Mail could be lost if some but not all
1748 deliveries of a message addressed to multiple users fail; such
1749 deliveries are not retried.
1751 Send comments, bug reports, gripes, and the like to the
1752 fetchmail-friends list <fetchmail-friends@ccil.org>. An HTML FAQ is
1753 available at the fetchmail home page; surf to
1754 http://www.tuxedo.org/~esr/fetchmail or do a WWW search for pages with
1755 `fetchmail' in their titles.
1758 elm(1), mail(1), sendmail(8), popd(8), imapd(8)
1759 .SH APPLICABLE STANDARDS
1762 RFC 821, RFC 1869, RFC 1652, RFC 1870, RFC1983, RFC 1985
1771 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1939
1774 RFC 1460, RFC 1725, RFC 1939
1783 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061
projects / ~andy / fetchmail / blob