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 manual page.)
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, \fIexim\fR, or \fIqmail\fR). All the
45 delivery-control mechanisms (such as \fI.forward\fR files) normally
46 available through your system MDA and local delivery agents will
51 is available, it will assist you in setting up and editing a
52 fetchmailrc configuration. It runs under X and requires that the
53 language Python and the Tk toolkit be present on your system. If
54 you are first setting up fetchmail for single-user mode, it is
55 recommended that you use Novice mode. Expert mode provides
56 complete control of fetchmail configuration, including the
57 multidrop features. In either case, the `Autoprobe' button
58 will tell you the most capable protocol a given mailserver
59 supported, and warn you of potential problems with that server.
64 is controlled by command-line options and a run control file,
65 .IR ~/.fetchmailrc\fR ,
66 the syntax of which we describe in a later section (this file is what
67 the \fIfetchmailconf\fR program edits). Command-line options override
71 Each server name that you specify following the options on the
72 command line will be queried. If you don't specify any servers
73 on the command line, each `poll' entry in your
77 To facilitate the use of
79 in scripts and pipelines, it returns an appropriate exit code upon
80 termination -- see EXIT CODES below.
82 The following options modify the behavior of \fIfetchmail\fR. It is
83 seldom necessary to specify any of these once you have a
84 working \fI.fetchmailrc\fR file set up.
86 Almost all options have a corresponding keyword which can be used to
91 Some special options are not covered here, but are documented instead
92 in sections on AUTHENTICATION and DAEMON MODE which follow.
96 Displays the version information for your copy of
98 No mail fetch is performed.
99 Instead, for each server specified, all the option information
100 that would be computed if
102 were connecting to that server is displayed. Any non-printables in
103 passwords or other string names are shown as backslashed C-like
104 escape sequences. This option is useful for verifying that your
105 options are set the way you want them.
108 Return a status code to indicate whether there is mail waiting,
109 without actually fetching or deleting mail (see EXIT CODES below).
110 This option turns off daemon mode (in which it would be useless). It
111 doesn't play well with queries to multiple sites, and doesn't work
112 with ETRN. It will return a false positive if you leave read but
113 undeleted mail in your server mailbox and your fetch protocol can't
114 tell kept messages from new ones. This means it will work with IMAP,
115 not work with POP2, and may occasionally flake out under POP3.
118 Silent mode. Suppresses all progress/status messages that are
119 normally echoed to standard error during a fetch (but does not
120 suppress actual error messages). The --verbose option overrides this.
123 Verbose mode. All control messages passed between
125 and the mailserver are echoed to stderr. Overrides --silent.
126 Doubling this option (-v -v) causes extra diagnostic information
132 Retrieve both old (seen) and new messages from the mailserver. The
133 default is to fetch only messages the server has not marked seen.
134 Under POP3, this option also forces the use of RETR rather than TOP.
135 Note that POP2 retrieval behaves as though --all is always on (see
136 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN.
140 Keep retrieved messages on the remote mailserver. Normally, messages
141 are deleted from the folder on the mailserver after they have been retrieved.
144 option causes retrieved messages to remain in your folder on the
145 mailserver. This option does not work with ETRN.
149 Delete retrieved messages from the remote mailserver. This
150 option forces retrieved mail to be deleted. It may be useful if
151 you have specified a default of \fBkeep\fR in your
152 \&\fI.fetchmailrc\fR. This option is forced on with ETRN.
155 POP3/IMAP only. Delete old (previously retrieved) messages from the mailserver
156 before retrieving new messages. This option does not work with ETRN.
157 Warning: if your local MTA hangs and fetchmail is aborted, the next
158 time you run fetchmail, it will delete mail that was never delivered to you.
159 What you probably want is the default setting: if you don't specify `-k', then
160 fetchmail will automatically delete messages after successful delivery.
161 .SS Protocol and Query Options
163 .B \-p, \--protocol proto
164 (Keyword: proto[col])
165 Specify the protocol to use when communicating with the remote
166 mailserver. If no protocol is specified, the default is AUTO.
168 may be one of the following:
171 Tries each of the supported protocols in turn, terminating after
172 any successful attempt.
174 Post Office Protocol 2
176 Post Office Protocol 3
178 Use POP3 with MD5 authentication.
180 Use POP3 with RPOP authentication.
182 Use POP3 with Kerberos V4 authentication on port 1109.
184 Use POP3 with Demon Internet's SDPS extensions.
186 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
188 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
189 with RFC 1731 Kerberos v4 authentication.
191 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
192 with RFC 1731 GSSAPI authentication.
194 Use the ESMTP ETRN option.
197 All these alternatives work in basically the same way (communicating
198 with standard server daemons to fetch mail already delivered to a
199 mailbox on the server) except ETRN. The ETRN mode allows you to ask a
200 compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
201 higher) to immediately open a sender-SMTP connection to your
202 client machine and begin forwarding any items addressed to your client
203 machine in the server's queue of undelivered mail.
207 Force UIDL use (effective only with POP3). Force client-side tracking
208 of `newness' of messages (UIDL stands for ``unique ID listing'' and is
209 described in RFC1725). Use with `keep' to use a mailbox as a baby
210 news drop for a group of users.
214 The port option permits you to specify a TCP/IP port to connect on.
215 This option will seldom be necessary as all the supported protocols have
216 well-established default port numbers.
220 The timeout option allows you to set a server-nonresponse
221 timeout in seconds. If a mailserver does not send a greeting message
222 or respond to commands for the given number of seconds,
223 \fIfetchmail\fR will hang up on it. Without such a timeout
224 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
225 down host. This would be particularly annoying for a \fIfetchmail\fR
226 running in background. There is a default timeout which fetchmail -V
227 will report. If a given connection receives too many timeouts in
228 succession, fetchmail will consider it wedged and stop retrying,
229 the calkling user will be notified by email if this happens.
233 The plugin option allows you to use an external program to establish the
234 TCP connection. This is useful if you want to use socks or need some
235 special firewalling setup. The program will be looked up in $PATH and
236 it will be passed two arguments: the name of the server and the name of
237 the port. Fetchmail will write to the plugin's stdin and read from
242 Identical to the plugin option above, but this one is used for the SMTP
243 connections (which will probably not need it, so it has been separated
246 .B \-r folder, --folder folder
248 Causes a specified non-default mail folder on the mailserver (or
249 comma-separated list of folders) to be retrieved. The syntax of the
250 folder name is server-dependent. This option is not available under
252 .SS Delivery Control Options
254 .B \-S hosts, --smtphost hosts
255 (Keyword: smtp[host])
256 Specify a hunt list of hosts to forward mail to (one or more
257 hostnames, comma-separated). In ETRN mode, set the host that the
258 mailserver is asked to ship mail to. Hosts are tried in list order;
259 the first one that is up becomes the forwarding or ETRN target for the
260 current run. Normally, `localhost' is added to the end of the list as
261 an invisible default. However, when using ETRN mode or Kerberos
262 authentication, the FQDN of the machine running fetchmail is added to
263 the end of the list as an invisible default. Each hostname may have a
264 port number following the host name. The port number is separated from
265 the host name by a slash; the default port is 25 (or ``smtp'' under IPv6).
268 --smtphost server1,server2/2525,server3
271 .B \-D domain, --smtpaddress domain
272 (Keyword: smtpaddress)
273 Specify the domain to be put in RCPT TO lines shipped to SMTP. The
274 name of the SMTP server (as specified by --smtphost, or defaulted to
275 "localhost") is used when this is not specified.
277 .B \-Z nnn, --antispam nnn[,nnn[,nnn...]]
279 Specifies the list of numeric SMTP errors that are to be interpreted
280 as a spam-block response from the listener. A value of -1 disables
281 this option. For the command-line option, the list values should
286 You can force mail to be passed to an MDA directly (rather than
287 forwarded to port 25) with the -mda or -m option. If \fIfetchmail\fR
288 is running as root, it sets its userid to that of the target user
289 while delivering mail through an MDA. Some possible MDAs are
290 "/usr/sbin/sendmail -oem -f %F %T", "/usr/bin/procmail -d %T"
291 and "/usr/bin/deliver". Local delivery addresses
292 will be inserted into the MDA command wherever you place a %T; the
293 mail message's From address will be inserted where you place an %F. Do
294 \fInot\fR use an MDA invocation like
295 "sendmail -oem -t" that dispatches on the contents of To/Cc/Bcc, it
296 will create mail loops and bring the just wrath of many postmasters
301 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
302 port \fImust\fR be explicitly specified (with a slash suffix) on each
303 host in the smtphost hunt list) if this option is selected; the
304 default port 25 will (in accordance with RFC 2033) not be accepted.
308 Append fetched mail to a BSMTP file. This simply contains the SMTP
309 commands that would normally be generated by fetchmail when passing
310 mail to an SMTP listener daemon. An argument of `-' causes the mail
311 to be written to standard output. Note that fetchmail's
312 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
313 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
314 MAILBOXES below apply.
315 .SS Resource Limit Control Options
319 Takes a maximum octet size argument. Messages larger than this size
320 will not be fetched, not be marked seen, and will be left on the
321 server (in foreground sessions, the progress messages will note that
322 they are "oversized"). An explicit --limit of 0 overrides any limits
323 set in your run control file. This option is intended for those
324 needing to strictly control fetch time due to expensive and variable
325 phone rates. In daemon mode, oversize notifications are mailed to the
326 calling user (see the --warnings option). This option does not work
331 Takes an interval in seconds. When you call
333 with a `limit' option in daemon mode, this controls the interval at
334 which warnings about oversized messages are mailed to the calling user
335 (or the user specified by the `postmaster' option). One such
336 notification is always mailed at the end of the the first poll that
337 the oversized message is detected. Thereafter, renotification is
338 suppressed until after the warning interval elapses (it will take
339 place at the end of the first following poll).
342 (Keyword: batchlimit)
343 Specify the maximum number of messages that will be shipped to an SMTP
344 listener before the connection is deliberately torn down and rebuilt
345 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
346 overrides any limits set in your run control file. While
347 \fBsendmail\fR(8) normally initiates delivery of a message immediately
348 after receiving the message terminator, some SMTP listeners are not so
349 prompt. MTAs like \fIqmail\fR(8) and \fIsmail\fR(8) may wait till the
350 delivery socket is shut down to deliver. This may produce annoying
353 is processing very large batches. Setting the batch limit to some
354 nonzero size will prevent these delays.
355 This option does not work with ETRN.
358 (Keyword: fetchlimit)
359 Limit the number of messages accepted from a given server in a single
360 poll. By default there is no limit. An explicit --fetchlimit of 0
361 overrides any limits set in your run control file.
362 This option does not work with ETRN.
366 When talking to an IMAP server,
368 normally issues an EXPUNGE command after each deletion in order to
369 force the deletion to be done immediately. This is safest when your
370 connection to the server is flaky and expensive, as it avoids
371 resending duplicate mail after a line hit. However, on large
372 mailboxes the overhead of re-indexing after every message can slam the
373 server pretty hard, so if your connection is reliable it is good to do
374 expunges less frequently. If you specify this option to an integer N,
377 to only issue expunges on every Nth delete. An argument
378 of zero suppresses expunges entirely (so no expunges at all will be
379 done until the end of run).
380 This option does not work with ETRN, POP2, or POP3.
381 .SS Authentication Options
383 .B \-u name, --username name
384 (Keyword: user[name])
385 Specifies the user identification to be used when logging in to the mailserver.
386 The appropriate user identification is both server and user-dependent.
387 The default is your login name on the client machine that is running
389 See USER AUTHENTICATION below for a complete description.
391 .B \-I specification, --interface specification
393 Require that a specific interface device be up and have a specific local
394 IP address (or range) before polling. Frequently
396 is used over a transient point-to-point TCP/IP link established directly
397 to a mailserver via SLIP or PPP. That is a relatively secure channel.
398 But when other TCP/IP routes to the mailserver exist (e.g. when the link
399 is connected to an alternate ISP), your username and password may be
400 vulnerable to snooping (especially when daemon mode automatically polls
401 for mail, shipping a clear password over the net at predictable
402 intervals). The --interface option may be used to prevent this. When
403 the specified link is not up or is not connected to a matching IP
404 address, polling will be skipped. The format is:
406 interface/iii.iii.iii.iii/mmm.mmm.mmm.mmm
408 The field before the first slash is the interface name (i.e. sl0, ppp0
409 etc.). The field before the second slash is the acceptable IP address.
410 The field after the second slash is a mask which specifies a range of
411 IP addresses to accept. If no mask is present 255.255.255.255 is
412 assumed (i.e. an exact match). This option is currently only supported
415 .B \-M interface, --monitor interface
417 Daemon mode can cause transient links which are automatically taken down
418 after a period of inactivity (e.g. PPP links) to remain up
419 indefinitely. This option identifies a system TCP/IP interface to be
420 monitored for activity. After each poll interval, if the link is up but
421 no other activity has occurred on the link, then the poll will be
422 skipped. This option is currently only supported under Linux.
425 (Keyword: auth[enticate])
426 This option permits you to specify a preauthentication type (see USER
427 AUTHENTICATION below for details). The possible values are
428 \&`\fBpassword\fR', `\fBkerberos_v5\fR' and `\fBkerberos\fR' (or, for
429 excruciating exactness, `\fBkerberos_v4\fR'). This option is provided
430 primarily for developers; choosing KPOP protocol automatically selects
431 Kerberos preauthentication, and all other alternatives use password
432 authentication (though APOP uses a generated one-time key as the
433 password and IMAP-K4 uses RFC1731 Kerberos v4 authentication). This
434 option does not work with ETRN.
435 .SS Miscellaneous Options
437 .B \-f pathname, --fetchmailrc pathname
438 Specify a non-default name for the
440 run control file. The pathname argument must be either "-" (a single
441 dash, meaning to read the configuration from standard input) or a
442 filename. Unless the --version option is also on, a named file
443 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
446 .B \-i pathname, --idfile pathname
448 Specify an alternate name for the .fetchids file used to save POP3
452 (Keyword: no rewrite)
455 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
456 fetched mail so that any mail IDs local to the server are expanded to
457 full addresses (@ and the mailserver hostname are appended). This enables
458 replies on the client to get addressed correctly (otherwise your
459 mailer might think they should be addressed to local users on the
460 client machine!). This option disables the rewrite. (This option is
461 provided to pacify people who are paranoid about having an MTA edit
462 mail headers and want to know they can prevent it, but it is generally
463 not a good idea to actually turn off rewrite.)
464 When using ETRN, the rewrite option is ineffective.
468 This option changes the header
470 assumes will carry a copy of the mail's envelope address. Normally
471 this is `X-Envelope-To' but as this header is not standard, practice
472 varies. See the discussion of multidrop address handling below. As a
473 special case, `envelope "Received"' enables parsing of sendmail-style
474 Received lines. This is the default, and it should not be necessary
475 unless you have globally disabled Received parsing with `no envelope'
476 in the \fI.fetchmailrc\fR file.
480 The string prefix assigned to this option will be removed from the user
481 name found in the header specified with the \fIenvelope\fR option
482 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
483 if either is applicable). This option is useful if you are using
485 to collect the mail for an entire domain and your ISP (or your mail
486 redirection provider) is using qmail.
487 One of the basic features of qmail is the
491 message header. Whenever qmail delivers a message to a local mailbox
492 it puts the username and hostname of the envelope recipient on this
493 line. The major reason for this is to prevent mail loops. To set up
494 qmail to batch mail for a disconnected site the ISP-mailhost will have
495 normally put that site in its `Virtualhosts' control file so it will
496 add a prefix to all mail addresses for this site. This results in mail
497 sent to 'username@userhost.userdom.dom.com' having a
498 \&`Delivered-To:' line of the form:
500 Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
502 The ISP can make the 'mbox-userstr-' prefix anything they choose
503 but a string matching the user host name is likely.
504 By using the option `envelope Delivered-To:' you can make fetchmail reliably
505 identify the original envelope recipient, but you have to strip the
506 `mbox-userstr-' prefix to deliver to the correct user.
507 This is what this option is for.
512 file, interpret any command-line options specified, and dump a
513 configuration report to standard output. The configuration report is
514 a data structure assignment in the language Python. This option
515 is meant to be used with an interactive
517 editor written in Python.
519 .SH USER AUTHENTICATION AND ENCRYPTION
520 Every mode except ETRN requires authentication of the client.
521 Normal user authentication in
523 is very much like the authentication mechanism of
525 The correct user-id and password depend upon the underlying security
526 system at the mailserver.
528 If the mailserver is a Unix machine on which you have an ordinary user
529 account, your regular login name and password are used with
531 If you use the same login name on both the server and the client machines,
532 you needn't worry about specifying a user-id with the
535 the default behavior is to use your login name on the client machine as the
536 user-id on the server machine. If you use a different login name
537 on the server machine, specify that login name with the
539 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
544 fetchmail -u jsmith mailgrunt
546 The default behavior of
548 is to prompt you for your mailserver password before the connection is
549 established. This is the safest way to use
551 and ensures that your password will not be compromised. You may also specify
552 your password in your
554 file. This is convenient when using
556 in daemon mode or with scripts.
558 If you do not specify a password, and
560 cannot extract one from your
562 file, it will look for a
564 file in your home directory before requesting one interactively; if an
565 entry matching the mailserver is found in that file, the password will
566 be used. Fetchmail first looks for a match on poll name; if it finds none,
567 it checks for a match on via name. See the
569 man page for details of the syntax of the
571 file. (This feature may allow you to avoid duplicating password
572 information in more than one file.)
574 On mailservers that do not provide ordinary user accounts, your user-id and
575 password are usually assigned by the server administrator when you apply for
576 a mailbox on the server. Contact your server administrator if you don't know
577 the correct user-id and password for your mailbox account.
579 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
580 independent authentication using the
582 file on the mailserver side. Under this RPOP variant, a fixed
583 per-user ID equivalent to a password was sent in clear over a link to
584 a reserved port, with the command RPOP rather than PASS to alert the
585 server that it should do special checking. RPOP is supported
588 (you can specify `protocol RPOP' to have the program send `RPOP'
589 rather than `PASS') but its use is strongly discouraged. This
590 facility was vulnerable to spoofing and was withdrawn in RFC1460.
592 RFC1460 introduced APOP authentication. In this variant of POP3,
593 you register an APOP password on your server host (the program
594 to do this with on the server is probably called \fIpopauth\fR(8)). You
595 put the same password in your
599 logs in, it sends a cryptographically secure hash of your password and
600 the server greeting time to the server, which can verify it by
601 checking its authorization database.
603 If your \fIfetchmail\fR was built with Kerberos support and you specify
604 Kerberos preauthentication (either with --auth or the \fI.fetchmailrc\fR
605 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
606 ticket from the mailserver at the start of each query. Note: if
607 either the pollnane or via name is `hesiod', fetchmail will try to use
608 Hesiod to look up the mailserver.
610 If you use IMAP-K4, \fIfetchmail\fR will expect the IMAP server to have
611 RFC1731-conformant AUTHENTICATE KERBEROS_V4 capability, and will use it.
613 If you use IMAP-GSS, \fIfetchmail\fR will expect the IMAP server to have
614 RFC1731-conformant AUTHENTICATE GSSAPI capability, and will use it.
615 Currently this has only been tested over Kerberos V, so you're expected
616 to already have a ticket-granting ticket. You may pass a username different
617 from your principal name using the standard \fB--user\fR command or by
618 the \fI.fetchmailrc\fR option \fBuser\fR.
620 If you are using POP3, and the server issues a one-time-password
621 challenge conforming to RFC1938, \fIfetchmail\fR will use your
622 password as a pass phrase to generate the required response. This
623 avoids sending secrets over the net unencrypted.
625 Compuserve's RPA authentication (similar to APOP) is supported. If
626 you are using POP3, and the RPA code has been compiled into your
627 binary, and you query a server in the Compuserve csi.com domain,
628 \fIfetchmail\fR will try to perform an RPA pass-phrase authentication
629 instead of sending over the password en clair.
631 If you are using IPsec, the -T (--netsec) option can be used to pass
632 an IP security request to be used when outgoing IP connections are
633 initialized. You can also do this using the `netsec' server option
634 in the .fetchmailrc file. In either case, the option value is a
635 string in the format accepted by the net_security_strtorequest()
636 function of the inet6_apps library.
645 in daemon mode. You must specify a numeric argument which is a
646 polling interval in seconds.
650 puts itself in background and runs forever, querying each specified
651 host and then sleeping for the given polling interval.
657 will, therefore, poll all the hosts described in your
659 file (except those explicitly excluded with the `skip' verb) once
660 every fifteen minutes.
662 It is possible to set a polling interval
665 file by saying `set daemon <interval>', where <interval> is an
666 integer number of seconds. If you do this, fetchmail will always
667 start in daemon mode unless you override it with the command-line
668 option --daemon 0 or -d0.
670 Only one daemon process is permitted per user; in daemon mode,
672 makes a per-user lockfile to guarantee this.
674 Normally, calling fetchmail with a daemon in the background sends a
675 wakeup signal to the daemon, forcing it to poll mailservers
676 immediately. (The wakeup signal is SIGHUP if fetchmail is running as
677 root, SIGUSR1 otherwise.) The wakeup action also clears any `wedged'
678 flags indicating that connections have wedged due to failed
679 authentication or multiple timeouts.
683 will kill a running daemon process instead of waking it up (if there
686 notifies you). If the --quit option is the only command-line option,
687 that's all there is to it.
689 The quit option may also be mixed with other command-line options; its
690 effect is to kill any running daemon before doing what the other
691 options specify in combination with the rc file.
697 option (keyword: set logfile) allows you to redirect status messages
698 emitted while detached into a specified logfile (follow the
699 option with the logfile name). The logfile is opened for append, so
700 previous messages aren't deleted. This is primarily useful for
701 debugging configurations.
705 option (keyword: set syslog) allows you to redirect status and error
706 messages emitted to the
708 system daemon if available.
709 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
710 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
711 This option is intended for logging status and error messages which
712 indicate the status of the daemon and the results while fetching mail
714 Error messages for command line options and parsing the \fI.fetchmailrc\fR
715 file are still written to stderr, or the specified log file if the
718 option turns off use of
720 assuming it's turned on in the
730 or --nodetach option suppresses backgrounding and detachment of the
731 daemon process from its control terminal. This is primarily useful
732 for debugging. Note that this also causes the logfile option to be
733 ignored (though perhaps it shouldn't).
735 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
736 transient errors (such as DNS failures or sendmail delivery refusals)
737 may force the fetchall option on for the duration of the next polling
738 cycle. This is a robustness feature. It means that if a message is
739 fetched (and thus marked seen by the mailserver) but not delivered
740 locally due to some transient error, it will be re-fetched during the
741 next poll cycle. (The IMAP logic doesn't delete messages until
742 they're delivered, so this problem does not arise.)
744 .SH ADMINISTRATIVE OPTIONS
748 option (keyword: set postmaster) specifies the last-resort username to
749 which multidrop mail is to be forwarded if no matching local recipient
750 can be found. Normally this is just the user who invoked fetchmail.
751 If the invoking user is root, then the default of this option is
752 the user `postmaster'.
756 option (keyword: set invisible) tries to make fetchmail invisible.
757 Normally, fetchmail behaves like any other MTA would -- it generates a
758 Received header into each message describing its place in the chain of
759 transmission, and tells the MTA it forwards to that the mail came from
760 the machine fetchmail itself is running on. If the invisible option
761 is on, the Received header is suppressed and fetchmail tries to spoof
762 the MTA it forwards to into thinking it came directly from the
765 .SH RETRIEVAL FAILURE MODES
766 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
767 bulletproof. In normal operation forwarding to port 25, no message is
768 ever deleted (or even marked for deletion) on the host until the SMTP
769 listener on the client has acknowledged to \fIfetchmail\fR that the
770 message has been accepted for delivery. When forwarding to an MDA,
771 however, there is more possibility of error (because there's no way
772 for fetchmail to get a reliable positive acknowledgement from the MDA).
774 The normal mode of \fIfetchmail\fR is to try to download only `new'
775 messages, leaving untouched (and undeleted) messages you have already
776 read directly on the server (or fetched with a previous \fIfetchmail
777 --keep\fR). But you may find that messages you've already read on the
778 server are being fetched (and deleted) even when you don't specify
779 --all. There are several reasons this can happen.
781 One could be that you're using POP2. The POP2 protocol includes no
782 representation of `new' or `old' state in messages, so \fIfetchmail\fR
783 must treat all messages as new all the time. But POP2 is obsolete, so
786 Under POP3, blame RFC1725. That version of the POP3 protocol
787 specification removed the LAST command, and some POP servers follow it
788 (you can verify this by invoking \fIfetchmail -v\fR to the mailserver
789 and watching the response to LAST early in the query). The
790 \fIfetchmail\fR code tries to compensate by using POP3's UID feature,
791 storing the identifiers of messages seen in each session until the
792 next session, in the \fI.fetchids\fR file. But this doesn't track
793 messages seen with other clients, or read directly with a mailer on
794 the host but not deleted afterward. A better solution would be to
797 Another potential POP3 problem might be servers that insert messages
798 in the middle of mailboxes (some VMS implementations of mail are
799 rumored to do this). The \fIfetchmail\fR code assumes that new
800 messages are appended to the end of the mailbox; when this is not true
801 it may treat some old messages as new and vice versa. The only
802 real fix for this problem is to switch to IMAP.
804 The IMAP code uses the presence or absence of the server flag \eSeen
805 to decide whether or not a message is new. Under Unix, it counts on
806 your IMAP server to notice the BSD-style Status flags set by mail user
807 agents and set the \eSeen flag from them when appropriate. All Unix
808 IMAP servers we know of do this, though it's not specified by the IMAP
809 RFCs. If you ever trip over a server that doesn't, the symptom will
810 be that messages you have already read on your host will look new to
811 the server. In this (unlikely) case, only messages you fetched with
812 \fIfetchmail --keep\fR will be both undeleted and marked old.
814 In ETRN mode, \fIfetchmail\fR does not actually retrieve messages;
815 instead, it asks the server's SMTP listener to start a queue flush
816 to the client via SMTP. Therefore it sends only undelivered messages.
819 Many SMTP listeners allow administrators to set up `spam filters' that
820 block unsolicited email from specified domains. A MAIL FROM or DATA line that
821 triggers this feature will elicit an SMTP response which
822 (unfortunately) varies according to the listener.
826 return an error code of 571. This return value
827 is blessed by RFC1893 as "Delivery not authorized, message refused".
829 According to current drafts of the replacement for RFC821, the correct
830 thing to return in this situation is 550 "Requested action not taken:
831 mailbox unavailable" (the draft adds "[E.g., mailbox not found, no
832 access, or command rejected for policy reasons].").
836 MTA returns 501 "Syntax error in parameters or arguments", but will
841 code recognizes and discards the message on any of a list of responses
842 that defaults to [571, 550, 501] but can be set with the `antispam'
845 circumstance under which fetchmail ever discards mail.
849 is fetching from an IMAP server, the antispam response will be detected and
850 the message rejected immediately after the headers have been fetched,
851 without reading the message body. Thus, you won't pay for downloading
854 Mail that is spam-blocked triggers an RFC1892 bounce message informing
855 the originator that we do not accept mail from it.
857 .SH SMTP/ESMTP ERROR HANDLING
858 Besides the spam-blocking described above,fetchmail takes special
859 actions on the following SMTP/ESMTP error responses
861 452 (insufficient system storage)
862 Leave the message in the server mailbox for later retrieval.
864 552 (message exceeds fixed maximum message size)
865 Delete the message from the server. Send bounce-mail to the originator.
867 553 (invalid sending domain)
868 Delete the message from the server. Send bounce-mail to the originator.
870 Other errors trigger bounce mail back to the originator.
872 .SH THE RUN CONTROL FILE
873 The preferred way to set up fetchmail is to write a
874 \&\fI.fetchmailrc\fR file in your home directory (you may do this
875 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
876 When there is a conflict between the command-line arguments and the
877 arguments in this file, the command-line arguments take precedence.
879 To protect the security of your passwords, when --version is not on
880 your \fI~/.fetchmailrc\fR may not have more than 0600 (u=rw,g=,o=) permissions;
882 will complain and exit otherwise.
884 You may read the \fI.fetchmailrc\fR file as a list of commands to
887 is called with no arguments.
888 .SS Run Control Syntax
890 Comments begin with a '#' and extend through the end of the line.
891 Otherwise the file consists of a series of server entries or global
892 option statements in a free-format, token-oriented syntax.
894 There are four kinds of tokens: grammar keywords, numbers
895 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
896 A quoted string is bounded by double quotes and may contain
897 whitespace (and quoted digits are treated as a string). An unquoted
898 string is any whitespace-delimited token that is neither numeric, string
899 quoted nor contains the special characters `,', `;', `:', or `='.
901 Any amount of whitespace separates tokens in server entries, but is
902 otherwise ignored. You may use standard C-style escapes (\en, \et,
903 \eb, octal, and hex) to embed non-printable characters or string
904 delimiters in strings.
906 Each server entry consists of one of the keywords `poll' or `skip',
907 followed by a server name, followed by server options, followed by any
908 number of user descriptions. Note: the most common cause of syntax
909 errors is mixing up user and server options.
911 For backward compatibility, the word `server' is a synonym for `poll'.
913 You can use the noise keywords `and', `with',
914 \&`has', `wants', and `options' anywhere in an entry to make
915 it resemble English. They're ignored, but but can make entries much
916 easier to read at a glance. The punctuation characters ':', ';' and
917 \&',' are also ignored.
920 The `poll' verb tells fetchmail to query this host when it is run with
921 no arguments. The `skip' verb tells
923 not to poll this host unless it is explicitly named on the command
924 line. (The `skip' verb allows you to experiment with test entries
925 safely, or easily disable entries for hosts that are temporarily down.)
927 .SS Keyword/Option Summary
928 Here are the legal options. Keyword suffixes enclosed in
929 square brackets are optional. Those corresponding to command-line
930 options are followed by `-' and the appropriate option letter.
932 Here are the legal global options:
939 Set a background poll interval in seconds
942 Give the name of the last-resort mail recipient
945 Name of a file to dump error and status messages to
948 Name of the file to store UID lists in
951 Do error logging through syslog(3).
954 Turn off error logging through syslog(3).
958 Here are the legal server options:
965 Specify DNS name of mailserver, overriding poll name
968 Specify protocol (case insensitive):
969 POP2, POP3, IMAP, IMAP-K4, IMAP-GSS, APOP, KPOP
972 Specify TCP/IP service port
975 Set preauthentication type (default `password')
978 Server inactivity timeout in seconds (default 300)
981 Specify envelope-address header name
984 Disable looking for envelope address
987 Qmail virtual domain prefix to remove from user name
990 Specify alternate DNS names of mailserver
993 specify IP interface(s) that must be up for server poll to take place
996 Specify IP address to monitor for activity
999 Specify command through which to make server connections.
1002 Specify command through which to make listener connections.
1005 Enable DNS lookup for multidrop (default)
1008 Disable DNS lookup for multidrop
1011 Do comparison by IP address for multidrop
1014 Do comparison by name for multidrop (default)
1017 Force POP3 to use client-side UIDLs
1020 Turn off POP3 use of client-side UIDLs (default)
1024 Here are the legal user options:
1028 Keyword Opt Function
1031 Set remote user name
1032 (local user name if name followed by `here')
1035 Connect local and remote user names
1038 Connect local and remote user names
1041 Specify remote account password
1044 Specify remote folder to query
1047 Specify smtp host(s) to forward to
1050 Specify the domain to be put in RCPT TO lines
1053 Specify what SMTP returns are interpreted as spam-policy blocks
1056 Specify MDA for local delivery
1059 Specify BSMTP batch file to append to
1062 Command to be executed before each connection
1065 Command to be executed after each connection
1068 Don't delete seen messages from server
1071 Flush all seen messages before querying
1074 Fetch all messages whether seen or not
1077 Rewrite destination addresses for reply (default)
1080 Strip carriage returns from ends of lines
1083 Force carriage returns at ends of lines
1086 Force BODY=8BITMIME to ESMTP listener
1089 Strip Status and X-Mozilla-Status lines out of incoming mail
1092 Convert quoted-printable to 8-bit in MIME messages
1095 Delete seen messages from server (default)
1098 Don't flush all seen messages before querying (default)
1101 Retrieve only new messages (default)
1104 Don't rewrite headers
1107 Don't strip carriage returns (default)
1110 Don't force carriage returns at EOL (default)
1113 Don't force BODY=8BITMIME to ESMTP listener (default)
1116 Don't drop Status headers (default)
1119 Don't convert quoted-printable to 8-bit in MIME messages (default)
1122 Set message size limit
1125 Set message size warning interval
1128 Max # messages to fetch in single connect
1131 Max # messages to forward in single connect
1134 Perform an expunge on every #th message (IMAP only)
1137 String value is ignored by fetchmail (may be used by extension scripts)
1141 Remember that all user options must \fIfollow\fR all server options.
1143 In the .fetchmailrc file, the `envelope' string argument may be
1144 preceded by a whitespace-separated number. This number, if specified,
1145 is the number of such headers to skip (that is, an argument of 1
1146 selects the second header of the given type). This is sometime useful
1147 for ignoring bogus Received headers created by an ISP's local delivery
1149 .SS Keywords Not Corresponding To Option Switches
1151 The `folder' and `smtphost' options (unlike their command-line
1152 equivalents) can take a space- or comma-separated list of names
1155 All options correspond to the obvious command-line arguments, except
1156 the following: `via', `interval', `aka', `is', `to', `dns'/`no dns',
1157 `checkalias'/`no checkalias', `password', `preconnect', `postconnect',
1158 `localdomains', `stripcr'/`no stripcr', `forcecr'/`no forcecr',
1159 `pass8bits'/`no pass8bits' `dropstatus/no dropstatus', `mimedecode/no
1160 mimedecode', and `no envelope'.
1162 The `via' option is for use with ssh, or if you want to have more
1163 than one configuration pointing at the same site. If it is present,
1164 the string argument will be taken as the actual DNS name of the
1165 mailserver host to query.
1166 This will override the argument of poll, which can then simply be a
1167 distinct label for the configuration (e.g. what you would give on the
1168 command line to explicitly query this host).
1169 If the `via' name is `localhost', the poll name will also still be
1170 used as a possible match in multidrop mode; otherwise the `via' name
1171 will be used instead and the poll name will be purely a label.
1173 The `interval' option (which takes a numeric argument) allows you to poll a
1174 server less frequently than the basic poll interval. If you say
1175 \&`interval N' the server this option is attached to will only be
1176 queried every N poll intervals.
1178 The `is' or `to' keywords associate the following local (client)
1179 name(s) (or server-name to client-name mappings separated by =) with
1180 the mailserver user name in the entry. If an is/to list has `*' as
1181 its last name, unrecognized names are simply passed through.
1183 A single local name can be used to support redirecting your mail when
1184 your username on the client machine is different from your name on the
1185 mailserver. When there is only a single local name, mail is forwarded
1186 to that local username regardless of the message's Received, To, Cc,
1187 and Bcc headers. In this case
1189 never does DNS lookups.
1191 When there is more than one local name (or name mapping) the
1192 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1193 headers of retrieved mail (this is `multidrop mode'). It looks for
1194 addresses with hostname parts that match your poll name or your `via',
1195 `aka' or `localdomains' options, and usually also for hostname parts
1196 which DNS tells it are aliases of the mailserver. See the discussion
1197 of `dns', `checkalias', `localdomains', and `aka' for details on how
1198 matching addresses are handled.
1200 If \fIfetchmail\fR cannot match any mailserver usernames or
1201 localdomain addresses, the default recipient is the value of the
1202 `postmaster' global option if that has been set; otherwise it's the
1203 calling user (as set by the USER or LOGNAME variable in the
1206 The `dns' option (normally on) controls the way addresses from
1207 multidrop mailboxes are checked. On, it enables logic to check each
1208 host address that doesn't match an `aka' or `localdomains' declaration
1209 by looking it up with DNS. When a mailserver username is recognized
1210 attached to a matching hostname part, its local mapping is added to
1211 the list of local recipients.
1213 The `checkalias' option (normally off) extends the lookups performed
1214 by the `dns' keyword in multidrop mode, providing a way to cope with
1215 remote MTAs that identify themselves using their canonical name, while
1216 they're polled using an alias.
1217 When such a server is polled, checks to extract the envelope address
1220 reverts to delivery using the To/Cc/Bcc headers (See below
1221 `Header vs. Envelope addresses').
1222 Specifying this option instructs
1224 to retrieve all the IP addresses associated with both the poll name
1225 and the name used by the remote MTA and to do a comparison of the IP
1226 addresses. This comes in handy in situations where the remote server
1227 undergoes frequent canonical name changes, that would otherwise
1228 require modifications to the rcfile. `checkalias' has no effect if
1229 `no dns' is specified in the rcfile.
1231 The `aka' option is for use with multidrop mailboxes. It allows you
1232 to pre-declare a list of DNS aliases for a server. This is an
1233 optimization hack that allows you to trade space for speed. When
1235 while processing a multidrop mailbox, grovels through message headers
1236 looking for names of the mailserver, pre-declaring common ones can
1237 save it from having to do DNS lookups.
1239 The `localdomains' option allows you to declare a list of domains
1240 which fetchmail should consider local. When fetchmail is parsing
1241 address lines in multidrop modes, and a trailing segment of a host
1242 name matches a declared local domain, that address is passed through
1243 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1246 If you are using `localdomains', you may also need to specify \&`no
1247 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1248 an envelope address from the Received line or X-Envelope-To header or
1249 whatever header has been previously set by `envelope'. If you set `no
1250 envelope' in the defaults entry it is possible to undo that in
1251 individual entries by using `envelope <string>'. As a special case,
1252 \&`envelope "Received"' restores the default parsing of
1255 The \fBpassword\fR option requires a string argument, which is the password
1256 to be used with the entry's server.
1258 The `preconnect' keyword allows you to specify a shell command to be
1259 executed just before each time
1261 establishes a mailserver connection. This may be useful if you are
1262 attempting to set up secure POP connections with the aid of
1264 If the command returns a nonzero status, the poll of that mailserver
1267 Similarly, the `postconnect' keyword similarly allows you to specify a
1268 shell command to be executed just after each time a mailserver
1269 connection is taken down.
1271 The `forcecr' option controls whether lines terminated by LF only are
1272 given CRLF termination before forwarding. Strictly speaking RFC821
1273 requires this, but few MTAs enforce the requirement it so this option
1274 is normally off (only one such MTA, qmail, is in significant use at
1277 The `stripcr' option controls whether carriage returns are stripped
1278 out of retrieved mail before it is forwarded. It is normally not
1279 necessary to set this, because it defaults to `on' (CR stripping
1280 enabled) when there is an MDA declared but `off' (CR stripping
1281 disabled) when forwarding is via SMTP. If `stripcr' and `forcecr' are
1282 both on, `stripcr' will override.
1284 The `pass8bits' option exists to cope with Microsoft mail programs that
1285 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1286 this option off (the default) and such a header present,
1288 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1289 messages actually using 8-bit ISO or KOI-8 character sets, which will
1290 be garbled by having the high bits of all characters stripped. If
1291 \&`pass8bits' is on,
1293 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1294 the listener is 8-bit-clean (as all the major ones now are) the right
1295 thing will probably result.
1297 The `dropstatus' option controls whether nonempty Status and
1298 X-Mozilla-Status lines are retained in fetched mail (the default) or
1299 discarded. Retaining them allows your MUA to see what messages (if
1300 any) were marked seen on the server. On the other hand, it can
1301 confuse some new-mail notifiers, which assume that anything with a
1302 Status line in it has been seen. (Note: the empty Status lines
1303 inserted by some buggy POP servers are unconditionally discarded.)
1305 The `mimedecode' option controls whether MIME messages using the
1306 quoted-printable encoding are automatically converted into pure
1307 8-bit data. If you are delivering mail to an ESMTP-capable,
1308 8-bit-clean listener (that includes all of the major programs
1309 like sendmail), then this will automatically convert quoted-printable
1310 message headers and data into 8-bit data, making it easier to
1311 understand when reading mail. If your e-mail programs know how to
1312 deal with MIME messages, then this option is not needed.
1314 The `properties' option is an extension mechanism. It takes a string
1315 argument, which is ignored by fetchmail itself. The string argument may be
1316 used to store configuration information for scripts which require it.
1317 In particular, the output of `--configdump' option will make properties
1318 associated with a user entry readily available to a Python script.
1320 .SS Miscellaneous Run Control Options
1321 The words `here' and `there' have useful English-like
1322 significance. Normally `user eric is esr' would mean that
1323 mail for the remote user `eric' is to be delivered to `esr',
1324 but you can make this clearer by saying `user eric there is esr here',
1325 or reverse it by saying `user esr here is eric there'
1327 Legal protocol identifiers for use with the `protocol' keyword are:
1334 imap-k4 (or IMAP-K4)
1335 imap-gss (or IMAP-GSS)
1340 Legal authentication types are `password' or `kerberos'. The former
1341 specifies authentication by normal transmission of a password (the
1342 password may be plaintext or subject to protocol-specific encryption
1343 as in APOP); the second tells \fIfetchmail\fR to try to get a Kerberos
1344 ticket at the start of each query instead, and send an arbitrary
1345 string as the password.
1347 Specifying `kpop' sets POP3 protocol over port 1109 with Kerberos V4
1348 preauthentication. These defaults may be overridden by later options.
1350 There are currently three global option statements; `set logfile'
1351 followed by a string sets the same global specified by --logfile. A
1352 command-line --logfile option will override this. Also, `set daemon'
1353 sets the poll interval as --daemon does. This can be overridden by
1354 a command-line --daemon option; in particular --daemon 0 can be used
1355 to force foreground operation. Finally, `set syslog' sends log
1356 messages to syslogd(8).
1358 .SH INTERACTION WITH RFC 822
1359 When trying to determine the originating address of a message,
1360 fetchmail looks through headers in the following order:
1370 The originating address is used for logging, and to set the MAIL FROM
1371 address when forwarding to SMTP. This order is intended to cope
1372 gracefully with receiving mailing list messages in multidrop mode. The
1373 intent is that if a local address doesn't exist, the bounce message
1374 won't be returned blindly to the author or to the list itself, but
1375 rather to the list manager (which is less annoying).
1377 In multidrop mode, destination headers are processed as follows:
1378 First, fetchmail looks for the Received: header (or whichever one is
1379 specified by the `envelope' option) to determine the local
1380 recipient address. If the mail is addressed to more than one recipient,
1381 the Received line won't contain any information regarding recipient addresses.
1383 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1384 lines. If they exists, they should contain the final recipients and
1385 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1386 lines doesn't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1387 looked for. (The presence of a Resent-To: is taken to imply that the
1388 person referred by the To: address has already received the original
1391 .SH CONFIGURATION EXAMPLES
1395 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1401 poll pop.provider.net protocol pop3 username jsmith password secret1
1404 Or, using some abbreviations:
1407 poll pop.provider.net proto pop3 user jsmith password secret1
1410 Multiple servers may be listed:
1413 poll pop.provider.net proto pop3 user jsmith pass secret1
1414 poll other.provider.net proto pop2 user John.Smith pass My^Hat
1417 Here's a version of those two with more whitespace and some noise words:
1420 poll pop.provider.net proto pop3
1421 user jsmith, with password secret1, is jsmith here;
1422 poll other.provider.net proto pop2:
1423 user John.Smith, with password My^Hat, is John.Smith here;
1426 This version is much easier to read and doesn't cost significantly
1427 more (parsing is done only once, at startup time).
1430 If you need to include whitespace in a parameter string, enclose the
1431 string in double quotes. Thus:
1434 poll mail.provider.net with proto pop3:
1435 user jsmith there has password "u can't krak this"
1436 is jws here and wants mda "/bin/mail"
1439 You may have an initial server description headed by the keyword
1440 `defaults' instead of `poll' followed by a name. Such a record
1441 is interpreted as defaults for all queries to use. It may be overwritten
1442 by individual server descriptions. So, you could write:
1447 poll pop.provider.net
1449 poll mail.provider.net
1450 user jjsmith there has password secret2
1453 It's possible to specify more than one user per server (this is only
1454 likely to be useful when running fetchmail in daemon mode as root).
1455 The `user' keyword leads off a user description, and every user specification
1456 in a multi-user entry must include it. Here's an example:
1459 poll pop.provider.net proto pop3 port 3111
1460 user jsmith with pass secret1 is smith here
1461 user jones with pass secret2 is jjones here
1464 This associates the local username `smith' with the pop.provider.net
1465 username `jsmith' and the local username `jjones' with the
1466 pop.provider.net username `jones'.
1468 Here's what a simple retrieval configuration for a multi-drop mailbox
1472 poll pop.provider.net:
1473 user maildrop with pass secret1 to golux hurkle=happy snark here
1476 This says that the mailbox of account `maildrop' on the server is a
1477 multi-drop box, and that messages in it should be parsed for the
1478 server user names `golux', `hurkle', and `snark'. It further
1479 specifies that `golux' and `snark' have the same name on the
1480 client as on the server, but mail for server user `hurkle' should be
1481 delivered to client user `happy'.
1483 Here's an example of another kind of multidrop connection:
1486 poll pop.provider.net localdomains loonytoons.org toons.org:
1487 user maildrop with pass secret1 to esr * here
1490 This also says that the mailbox of account `maildrop' on the server is
1491 a multi-drop box. It tells fetchmail that any address in the
1492 loonytoons.org or toons.org domains (including subdomain addresses like
1493 `joe@daffy.loonytoons.org') should be passed through to the local SMTP
1494 listener without modification. Be careful of mail loops if you do this!
1496 Here's an example configuration using ssh. The queries go through an
1497 ssh connecting local port 1234 to port 110 on mailhost.net; the
1498 preconnect command sets up the ssh.
1501 poll mailhost.net via localhost port 1234 with proto pop3:
1502 preconnect "ssh -f -L 1234:mailhost.net:110
1503 mailhost.net sleep 20 </dev/null >/dev/null";
1506 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
1507 Use the multiple-local-recipients feature with caution -- it can bite.
1508 Also note that all multidrop features are ineffective in ETRN mode.
1510 .SS Header vs. Envelope addresses
1511 The fundamental problem is that by having your mailserver toss several
1512 peoples' mail in a single maildrop box, you may have thrown away
1513 potentially vital information about who each piece of mail was
1514 actually addressed to (the `envelope address', as opposed to the
1515 header addresses in the RFC822 To/Cc/Bcc headers). This `envelope
1516 address' is the address you need in order to reroute mail properly.
1520 can deduce the envelope address. If the mailserver MTA is
1522 and the item of mail had just one recipient, the MTA will have written
1523 a `by/for' clause that gives the envelope addressee into its Received
1524 header. But this doesn't work reliably for other MTAs, nor if there is
1525 more than one recipient. By default, \fIfetchmail\fR looks for
1526 envelope addresses in these lines; you can restore this default with
1527 -E "Received" or \&`envelope Received'.
1529 Alternatively, some SMTP listeners and/or mail servers insert a header
1530 in each message containing a copy of the envelope addresses. This
1531 header (when it exists) is often `X-Envelope-To'. Fetchmail's
1532 assumption about this can be changed with the -E or `envelope' option.
1533 Note that writing an envelope header of this kind exposes the names of
1534 recipients (including blind-copy recipients) to all receivers of the
1535 messages; it is therefore regarded by some administrators as a
1536 security/privacy problem.
1538 A slight variation of the `X-Envelope-To' header is the `Delivered-To' put
1539 by qmail to avoid mail loops. It will probably prefix the user name with a
1540 string that normally matches the user's domain. To remove this prefix you
1541 can use the -Q or `qvirtual' option.
1543 Sometimes, unfortunately, neither of these methods works. When they
1544 all fail, fetchmail must fall back on the contents of To/Cc/Bcc
1545 headers to try to determine recipient addressees -- and these are not
1546 reliable. In particular, mailing-list software often ships mail with
1547 only the list broadcast address in the To header.
1551 cannot deduce a recipient address that is local, and the intended
1552 recipient address was anyone other than fetchmail's invoking user,
1553 mail will get lost. This is what makes the multidrop feature risky.
1555 A related problem is that when you blind-copy a mail message, the Bcc
1556 information is carried \fIonly\fR as envelope address (it's not put
1557 in the headers fetchmail can see unless there is an X-Envelope
1558 header). Thus, blind-copying to someone who gets mail over a
1559 fetchmail link will fail unless the the mailserver host routinely
1560 writes X-Envelope or an equivalent header into messages in your maildrop.
1562 .SS Good Ways To Use Multidrop Mailboxes
1563 Multiple local names can be used to administer a mailing list from the
1564 client side of a \fIfetchmail\fR collection. Suppose your name is
1565 \&`esr', and you want to both pick up your own mail and maintain a mailing
1566 list called (say) "fetchmail-friends", and you want to keep the alias
1567 list on your client machine.
1569 On your server, you can alias \&`fetchmail-friends' to `esr'; then, in
1570 your \fI.fetchmailrc\fR, declare \&`to esr fetchmail-friends here'.
1571 Then, when mail including `fetchmail-friends' as a local address
1572 gets fetched, the list name will be appended to the list of
1573 recipients your SMTP listener sees. Therefore it will undergo alias
1574 expansion locally. Be sure to include `esr' in the local alias
1575 expansion of fetchmail-friends, or you'll never see mail sent only to
1576 the list. Also be sure that your listener has the "me-too" option set
1577 (sendmail's -oXm command-line option or OXm declaration) so your name
1578 isn't removed from alias expansions in messages you send.
1580 This trick is not without its problems, however. You'll begin to see
1581 this when a message comes in that is addressed only to a mailing list
1582 you do \fInot\fR have declared as a local name. Each such message
1583 will feature an `X-Fetchmail-Warning' header which is generated
1584 because fetchmail cannot find a valid local name in the recipient
1585 addresses. Such messages default (as was described above) to being
1586 sent to the local user running
1588 but the program has no way to know that that's actually the right thing.
1590 .SS Bad Ways To Abuse Multidrop Mailboxes
1591 Multidrop mailboxes and
1593 serving multiple users in daemon mode do not mix. The problem, again, is
1594 mail from mailing lists, which typically does not have an individual
1595 recipient address on it. Unless
1597 can deduce an envelope address, such mail will only go to the account
1598 running fetchmail (probably root). Also, blind-copied users are very
1599 likely never to see their mail at all.
1601 If you're tempted to use
1603 to retrieve mail for multiple users from a single mail drop via POP or
1604 IMAP, think again (and reread the section on header and envelope
1605 addresses above). It would be smarter to just let the mail sit in the
1606 mailserver's queue and use fetchmail's ETRN mode to trigger SMTP sends
1607 periodically (of course, this means you have to poll more frequently
1608 than the mailserver's expiry period). If you can't arrange this, try
1609 setting up a UUCP feed.
1611 If you absolutely \fImust\fR use multidrop for this purpose, make sure
1612 your mailserver writes an envelope-address header that fetchmail can
1613 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
1616 .SS Speeding Up Multidrop Checking
1617 Normally, when multiple user are declared
1619 extracts recipient addresses as described above and checks each host
1620 part with DNS to see if it's an alias of the mailserver. If so, the
1621 name mappings described in the to ... here declaration are done and
1622 the mail locally delivered.
1624 This is the safest but also slowest method. To speed it up,
1625 pre-declare mailserver aliases with `aka'; these are checked before
1626 DNS lookups are done. If you're certain your aka list contains
1628 DNS aliases of the mailserver (and all MX names pointing at it)
1629 you can declare `no dns' to suppress DNS lookups entirely and
1630 \fIonly\fR match against the aka list.
1633 To facilitate the use of
1635 in shell scripts, an exit code is returned to give an indication
1636 of what occurred during a given connection.
1638 The exit codes returned by
1642 One or more messages were successfully retrieved (or, if the -c option
1643 was selected, were found waiting but not retrieved).
1645 There was no mail awaiting retrieval. (There may have been old mail still
1646 on the server but not selected for retrieval.)
1648 An error was encountered when attempting to open a socket to retrieve
1649 mail. If you don't know what a socket is, don't worry about it --
1650 just treat this as an 'unrecoverable error'.
1652 The user authentication step failed. This usually means that a bad
1653 user-id, password, or APOP id was specified.
1655 Some sort of fatal protocol error was detected.
1657 There was a syntax error in the arguments to
1660 The run control file had bad permissions.
1662 There was an error condition reported by the server. Can also
1665 timed out while waiting for the server.
1667 Client-side exclusion error. This means
1669 either found another copy of itself already running, or failed in such
1670 a way that it isn't sure whether another copy is running.
1672 The user authentication step failed because the server responded "lock
1673 busy". Try again after a brief pause! This error is not implemented
1674 for all protocols, nor for all servers. If not implemented for your
1675 server, "3" will be returned instead, see above. May be returned when
1676 talking to qpopper or other servers that can respond with "lock busy"
1677 or some similar text containing the word "lock".
1681 run failed while trying to do an SMTP port open or transaction.
1683 Fatal DNS error. Fetchmail encountered an error while performing
1684 a DNS lookup at startup and could not proceed.
1686 BSMTP batch file could not be opened.
1688 Internal error. You should see a message on standard error with
1693 queries more than one host, return status is 0 if \fIany\fR query
1694 successfully retrieved mail. Otherwise the returned error status is
1695 that of the last host queried.
1698 Eric S. Raymond <esr@snark.thyrsus.com>.
1699 This program is descended from and replaces
1701 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
1702 but some of its interface design is directly traceable to that
1708 default run control file
1711 default location of file associating hosts with last message IDs seen
1712 (used only with newer RFC1725-compliant POP3 servers supporting the
1716 your FTP run control file, which (if present) will be searched for
1717 passwords as a last resort before prompting for one interactively.
1720 lock file to help prevent concurrent runs (non-root mode).
1722 /var/run/fetchmail.pid
1723 lock file to help prevent concurrent runs (root mode, Linux systems).
1726 lock file to help prevent concurrent runs (root mode, systems without /var/run).
1729 For correct initialization,
1731 requires either that both the USER and HOME environment variables are
1732 correctly set, or that \fBgetpwuid\fR(3) be able to retrieve a password
1733 entry from your user ID.
1738 daemon is running as root, SIGHUP wakes it up from its sleep phase and
1739 forces a poll of all non-skipped servers (this is in accordance with
1740 the usual conventions for system daemons).
1744 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
1745 so SIGHUP due to logout can retain the default action of killing it).
1749 in foreground while a background fetchmail is running will do
1750 whichever of these is appropriate to wake it up.
1752 .SH BUGS AND KNOWN PROBLEMS
1753 Enabling the `mimedecode' option (which defaults to off) may render
1754 invalid any PGP signatures attached to mail with quoted-printable headers.
1755 This bug will be fixed in a future version.
1757 The RFC822 address parser used in multidrop mode chokes on some
1758 @-addresses that are technically legal but bizarre. Strange uses of
1759 quoting and embedded comments are likely to confuse it.
1761 In a message with multiple envelope headers, only the last one
1762 processed will be visible to fetchmail. To get around this, use a
1763 mailserver-side filter that consolidates the contents of all envelope
1764 headers into a single one (procmail, mailagent, or maildrop can be
1765 orogrammed to do this fairly easily).
1767 Use of any of the supported protocols other than POP3 with OTP or RPA, APOP,
1768 KPOP, IMAP-K4, IMAP-GSS, or ETRN requires that the program send unencrypted
1769 passwords over the TCP/IP connection to the mailserver. This creates
1770 a risk that name/password pairs might be snaffled with a packet
1771 sniffer or more sophisticated monitoring software. Under Linux, the
1772 --interface option can be used to restrict polling to availability of
1773 a specific interface device with a specific local IP address, but
1774 snooping is still possible if (a) either host has a network device
1775 that can be opened in promiscuous mode, or (b) the intervening network
1778 Use of the %F or %T escapes in an mda option could open a security
1779 hole, because they pass text manipulable by an attacker to a shell
1780 command. Potential shell characters are replaced by `_' before
1781 execution. The hole is further reduced by the fact that fetchmail
1782 temporarily discards any suid privileges it may have while running the
1783 MDA. For maximum safety, however, don't use an mda command containing
1784 %F or %T when fetchmail is run from the root account itself.
1786 Fetchmail's method of sending bouncemail requires that port 25 of localhost
1787 be available for sending mail via SMTP.
1789 Send comments, bug reports, gripes, and the like to the
1790 fetchmail-friends list <fetchmail-friends@ccil.org>. An HTML FAQ is
1791 available at the fetchmail home page; surf to
1792 http://www.tuxedo.org/~esr/fetchmail or do a WWW search for pages with
1793 `fetchmail' in their titles.
1796 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8)
1797 .SH APPLICABLE STANDARDS
1800 RFC 821, RFC 1869, RFC 1652, RFC 1870, RFC1983, RFC 1985
1803 RFC 822, RFC 1892, RFC1894
1809 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1939
1812 RFC 1460, RFC 1725, RFC 1939
1821 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061