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
61 is controlled by command-line options and a run control file,
62 .IR ~/.fetchmailrc\fR ,
63 the syntax of which we describe in a later section (this file is what
64 the \fIfetchmailconf\fR program edits). Command-line options override
68 Each server name that you specify following the options on the
69 command line will be queried. If you don't specify any servers
70 on the command line, each server in your
74 To facilitate the use of
76 In scripts, pipelines, etc., it returns an appropriate exit code upon
77 termination -- see EXIT CODES below.
78 The following options modify the behavior of \fIfetchmail\fR. It is
79 seldom necessary to specify any of these once you have a
80 working \fI.fetchmailrc\fR file set up.
82 Almost all options have a corresponding keyword which can be used to
87 Some special options are not covered here, but are documented insttead
88 in sections on AUTHENTICATION and DAEMON MODE which follows.
92 Displays the version information for your copy of
94 No mail fetch is performed.
95 Instead, for each server specified, all option information
96 that would be computed if
98 were connecting to that server is displayed. Any non-printables in
99 passwords or other string names are shown as backslashed C-like
100 escape sequences. This option is useful for verifying that your
101 options are set the way you want them.
104 Return a status code to indicate whether there is mail waiting,
105 without actually fetching or deleting mail (see EXIT CODES below).
106 This option turns off daemon mode (in which it would be useless). It
107 doesn't play well with queries to multiple sites, and doesn't work
108 with ETRN. It will return a false positive if you leave read but
109 undeleted mail in your server mailbox and your fetch protocol can't
110 tell kept messages from new ones. This means it will work with IMAP,
111 not work with POP2, and may occasionally flake out under POP3.
114 Silent mode. Suppresses all progress/status messages that are
115 normally echoed to standard error during a fetch (but does not
116 suppress actual error messages). The --verbose option overrides this.
119 Verbose mode. All control messages passed between
121 and the mailserver are echoed to stderr. Overrides --silent.
126 Retrieve both old (seen) and new messages from the mailserver. The
127 default is to fetch only messages the server has not marked seen.
128 Under POP3, this option also forces the use of RETR rather than TOP.
129 Note that POP2 retrieval behaves as though --all is always on (see
130 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN.
134 Keep retrieved messages on the remote mailserver. Normally, messages
135 are deleted from the folder on the mailserver after they have been retrieved.
138 option causes retrieved messages to remain in your folder on the
139 mailserver. This option does not work with ETRN.
143 Delete retrieved messages from the remote mailserver. This
144 option forces retrieved mail to be deleted. It may be useful if
145 you have specified a default of \fBkeep\fR in your
146 \&\fI.fetchmailrc\fR. This option is forced on with ETRN.
149 POP3/IMAP only. Delete old (previously retrieved) messages from the mailserver
150 before retrieving new messages. This option does not work with ETRN.
151 Warning: if your local MTA hangs and fetchmail is aborted, the next
152 time you run fetchmail, it will delete mail that was never delivered to you.
153 What you probably want is the default setting: if you don't specify `-k', then
154 fetchmail will automatically delete messages after successful delivery.
155 .SS Protocol and Query Options
157 .B \-p, \--protocol proto
158 (Keyword: proto[col])
159 Specify the protocol to used when communicating with the remote
160 mailserver. If no protocol is specified,
162 will try each of the supported protocols in turn, terminating after
163 any successful attempt.
165 may be one of the following:
168 Post Office Protocol 2
170 Post Office Protocol 3
172 Use POP3 with MD5 authentication.
174 Use POP3 with RPOP authentication.
176 Use POP3 with Kerberos V4 authentication on port 1109.
178 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
180 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
181 with RFC 1731 Kerberos v4 authentication.
183 IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities)
184 with RFC 1731 GSSAPI authentication.
186 Use the ESMTP ETRN option.
188 All these alternatives work in basically the same way (communicating
189 with standard server daemons to fetch mail already delivered to a
190 mailbox on the server) except ETRN. The ETRN mode allows you to ask a
191 compliant ESMTP server (such as BSD sendmail at release 8.8.0 or
192 higher) to immediately open a sender-SMTP connection to your
193 client machine and begin forwarding any items addressed to your client
194 machine in the server's queue of undelivered mail.
198 Force UIDL use (effective only with POP3). Force client-side tracking
199 of `newness' of messages (UIDL stands for ``unique ID listing'' and is
200 described in RFC1725). Use with `keep' to use a mailbox as a baby
201 news drop for a group of users.
205 The option permits you to specify a TCP/IP port to connect on.
206 This option will seldom be necessary as all the supported protocols have
207 well-established default port numbers.
209 .B \-r folder, --folder folder
211 Causes a specified non-default mail folder on the mailserver (or
212 comma-separated list of folders) to be retrieved. The syntax of the
213 folder name is server-dependent. This option is not available under
215 .SS Delivery Control Options
217 .B \-S host, --smtphost host
218 (Keyword: smtp[host])
219 Specify a hunt list of hosts to forward mail to (one or more
220 hostnames, comma-separated). In ETRN mode, set the host that the
221 mailserver is asked to ship mail to. Hosts are tried in list order;
222 the first one that is up becomes the forwarding or ETRN target for the
223 current run. In ETRN mode, the FQDN of the machine running fetchmail
224 is added to the end of the list as an invisible default; in all other
225 modes `localhost' is added to the end of the list as an invisible
226 default. Each hostname may have a '/'-delimited suffix specifying a
227 port or service to forward to; the default is 25 (or "smtp" under IPv6).
229 .B \-D domain, --smtpaddress domain
230 (Keyword: smtpaddress)
231 Specify the domain to be put in RCPT TO lines shipped to SMTP. The
232 name of the SMTP server (as specified by --smtphost, or defaulted to
233 "localhost") is used when this is not specified.
235 .B \-Z nnn, --antispam nnn[,nnn[,nnn...]]
237 Specifies the list of numeric SMTP errors that are to be interpreted
238 as a spam-block response from the listener. A value of -1 disables
239 this option. For the command-line option, the list values should
244 You can force mail to be passed to an MDA directly (rather than
245 forwarded to port 25) with the -mda or -m option. If \fIfetchmail\fR
246 is running as root, it sets its userid to that of the target user
247 while delivering mail through an MDA. Some possible MDAs are
248 "/usr/sbin/sendmail -oem", "/usr/lib/sendmail -oem",
249 "/usr/bin/formail", and "/usr/bin/deliver". Local delivery addresses
250 will be inserted into the MDA command wherever you place a %T; the
251 mail message's From address will be inserted where you place an %F. Do
252 \fInot\fR use an MDA invocation like
253 "sendmail -oem -t" that dispatches on the contents of To/Cc/Bcc, it
254 will create mail loops and bring the just wrath of many postmasters
256 .SS Resource Limit Control Options
260 Takes a maximum octet size argument. Messages larger than this size
261 will not be fetched, not be marked seen, and will be left on the
262 server (in foreground sessions, the progress messages will note that
263 they are "oversized"). An explicit --limit of 0 overrides any limits set
264 in your run control file. This option is intended for those needing to
265 strictly control fetch time in interactive mode. It may not be used
266 with daemon mode, as users would never receive a notification that
267 messages were waiting. This option does not work with ETRN.
270 (Keyword: batchlimit)
271 Specify the maximum number of messages that will be shipped to an SMTP
272 listener before the connection is deliberately torn down and rebuilt
273 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
274 overrides any limits set in your run control file. While
275 \fBsendmail\fR(8) normally initiates delivery of a message immediately
276 after receiving the message terminator, some SMTP listeners are not so
277 prompt. MTAs like \fIqmail\fR(8) and \fIsmail\fR(8) may wait till the
278 delivery socket is shut down to deliver. This may produce annoying
281 is processing very large batches. Setting the batch limit to some
282 nonzero size will prevent these delays.
283 This option does not work with ETRN.
286 (Keyword: fetchlimit)
287 Limit the number of messages accepted from a given server in a single
288 poll. By default there is no limit. An explicit --fetchlimit of 0
289 overrides any limits set in your run control file.
290 This option does not work with ETRN.
294 When talking to an IMAP server,
296 normally issues an EXPUNGE command after each deletion in order to
297 force the deletion to be done immediately. This is safest when your
298 connection to the server is flaky and expensive, as it avoids
299 resending duplicate mail after a line hit. However, on large
300 mailboxes the overhead of re-indexing after every message can slam the
301 server pretty hard, so if your connection is reliable it is good to do
302 expunges less frequently. If you specify this option to an integer N,
305 to only issue expunges on every Nth delete. An argument
306 of zero suppresses expunges entirely (so no expunges at all will be
307 done until the end of run).
308 This option does not work with ETRN, POP2, or POP3.
309 .SS Authentication Options
311 .B \-u name, --username name
312 (Keyword: user[name])
313 Specifies the user identification to be used when logging in to the mailserver.
314 The appropriate user identification is both server and user-dependent.
315 The default is your login name on the client machine that is running
317 See USER AUTHENTICATION below for a complete description.
319 .B \-I specification, --interface specification
321 Require that a specific interface device be up and have a specific local
322 IP address (or range) before polling. Frequently
324 is used over a transient point-to-point TCP/IP link established directly
325 to a mailserver via SLIP or PPP. That is a relatively secure channel.
326 But when other TCP/IP routes to the mailserver exist (e.g. when the link
327 is connected to an alternate ISP), your username and password may be
328 vulnerable to snooping (especially when daemon mode automatically polls
329 for mail, shipping a clear password over the net at predictable
330 intervals). The --interface option may be used to prevent this. When
331 the specified link is not up or is not connected to a matching IP
332 address, polling will be skipped. The format is:
334 interface/iii.iii.iii.iii/mmm.mmm.mmm.mmm
336 The field before the first slash is the interface name (i.e. sl0, ppp0
337 etc.). The field before the second slash is the acceptable IP address.
338 The field after the second slash is a mask which specifies a range of
339 IP addresses to accept. If no mask is present 255.255.255.255 is
340 assumed (i.e. an exact match). This option is currently only supported
343 .B \-M interface, --monitor interface
345 Daemon mode can cause transient links which are automatically taken down
346 after a period of inactivity (e.g. PPP links) to remain up
347 indefinitely. This option identifies a system TCP/IP interface to be
348 monitored for activity. After each poll interval, if the link is up but
349 no other activity has occurred on the link, then the poll will be
350 skipped. This option is currently only supported under Linux.
353 (Keyword: auth[enticate])
354 This option permits you to specify a preauthentication type (see USER
355 AUTHENTICATION below for details). The possible values are
356 \&`\fBpassword\fR', `\fBkerberos_v5\fR' and `\fBkerberos\fR' (or, for
357 excruciating exactness, `\fBkerberos_v4\fR'). This option is provided
358 primarily for developers; choosing KPOP protocol automatically selects
359 Kerberos preauthentication, and all other alternatives use password
360 authentication (though APOP uses a generated one-time key as the
361 password and IMAP-K4 uses RFC1731 Kerberos v4 authentication). This
362 option does not work with ETRN.
363 .SS Miscellaneous Options
365 .B \-f pathname, --fetchmailrc pathname
366 Specify a non-default name for the
368 run control file. Unless the --version option is also on, the file must have
369 permissions no more open than 0600 (u=rw,g=,o=) or else be /dev/null.
371 .B \-i pathname, --idfile pathname
373 Specify an alternate name for the .fetchids file used to save POP3
377 (Keyword: no rewrite)
380 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
381 fetched mail so that any mail IDs local to the server are expanded to
382 full addresses (@ and the mailserver hostname are appended). This enables
383 replies on the client to get addressed correctly (otherwise your
384 mailer might think they should be addressed to local users on the
385 client machine!). This option disables the rewrite. (This option is
386 provided to pacify people who are paranoid about having an MTA edit
387 mail headers and want to know they can prevent it, but it is generally
388 not a good idea to actually turn off rewrite.)
389 When using ETRN, the rewrite option is ineffective.
393 This option changes the header
395 assumes will carry a copy of the mail's envelope address. Normally
396 this is `X-Envelope-To' but as this header is not standard, practice
397 varies. See the discussion of multidrop address handling below. As a
398 special case, `envelope "Received"' enables parsing of sendmail-style
399 Received lines. This is the default, and it should not be necessary
400 unless you have globally disabled Received parsing with `no envelope'
401 in the \fI.fetchmailrc\fR file.
405 The string prefix assigned to this option will be removed from the user
406 name found in the header specified with the \fIenvelope\fR option
407 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
408 if either is applicable). This option is useful if you are using
410 to collect the mail for an entire domain and your ISP (or your mail
411 redirection provider) is using qmail.
412 One of the basic features of qmail is the
416 message header. Whenever qmail delivers a message to a local mailbox
417 it puts the username and hostname of the envelope recipient on this
418 line. The major reason for this is to prevent mail loops. To set up
419 qmail to batch mail for a disconnected site the ISP-mailhost will have
420 normally put that site in its `Virtualhosts' control file so it will
421 add a prefix to all mail addresses for this site. This results in mail
422 sent to 'username@userhost.userdom.dom.com' having a
423 \&`Delivered-To:' line of the form:
425 Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
427 The ISP can make the 'mbox-userstr-' prefix anything they choose
428 but a string matching the user host name is likely.
429 By using the option `envelope Delivered-To:' you can make fetchmail reliably
430 identify the original envelope recipient, but you have to strip the
431 `mbox-userstr-' prefix to deliver to the correct user.
432 This is what this option is for.
437 file, interpret any command-line options specified, and dump a
438 configuration report to standard output. The configuration report is
439 a data structure assignment in the language Python. This option
440 is meant to be used with an interactive
442 editor written in Python.
444 .SH USER AUTHENTICATION AND ENCRYPTION
445 Every mode except ETRN requires authentication of the client.
446 Normal user authentication in
448 is very much like the authentication mechanism of
450 The correct user-id and password depend upon the underlying security
451 system at the mailserver.
453 If the mailserver is a Unix machine on which you have an ordinary user
454 account, your regular login name and password are used with
456 If you use the same login name on both the server and the client machines,
457 you needn't worry about specifying a user-id with the
460 the default behavior is to use your login name on the client machine as the
461 user-id on the server machine. If you use a different login name
462 on the server machine, specify that login name with the
464 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
469 fetchmail -u jsmith mailgrunt
471 The default behavior of
473 is to prompt you for your mailserver password before the connection is
474 established. This is the safest way to use
476 and ensures that your password will not be compromised. You may also specify
477 your password in your
479 file. This is convenient when using
481 in daemon mode or with scripts.
483 If you do not specify a password, and
485 cannot extract one from your
487 file, it will look for a
489 file in your home directory before requesting one interactively; if an
490 entry matching the mailserver is found in that file, the password will
493 man page for details of the syntax of the
495 file. (This feature may allow you to avoid duplicating password
496 information in more than one file.)
498 On mailservers that do not provide ordinary user accounts, your user-id and
499 password are usually assigned by the server administrator when you apply for
500 a mailbox on the server. Contact your server administrator if you don't know
501 the correct user-id and password for your mailbox account.
503 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
504 independent authentication using the
506 file on the mailserver side. Under this RPOP variant, a fixed
507 per-user ID equivalent to a password was sent in clear over a link to
508 a reserved port, with the command RPOP rather than PASS to alert the
509 server that it should do special checking. RPOP is supported
512 (you can specify `protocol RPOP' to have the program send `RPOP'
513 rather than `PASS') but its use is strongly discouraged. This
514 facility was vulnerable to spoofing and was withdrawn in RFC1460.
516 RFC1460 introduced APOP authentication. In this variant of POP3,
517 you register an APOP password on your server host (the program
518 to do this with on the server is probably called \fIpopauth\fR(8)). You
519 put the same password in your
523 logs in, it sends a cryptographically secure hash of your password and
524 the server greeting time to the server, which can verify it by
525 checking its authorization database.
527 If your \fIfetchmail\fR was built with Kerberos support and you specify
528 Kerberos preauthentication (either with --auth or the \fI.fetchmailrc\fR
529 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
530 ticket from the mailserver at the start of each query.
532 If you use IMAP-K4, \fIfetchmail\fR will expect the IMAP server to have
533 RFC1731-conformant AUTHENTICATE KERBEROS_V4 capability, and will use it.
535 If you use IMAP-GSS, \fIfetchmail\fR will expect the IMAP server to have
536 RFC1731-conformant AUTHENTICATE GSSAPI capability, and will use it.
537 Currently this has only been tested over Kerberos V, so you're expected
538 to already have a ticket-granting ticket. You may pass a username different
539 from your principal name using the standard \fB--user\fR command or by
540 the \fI.fetchmailrc\fR option \fBuser\fR.
542 If you are using POP3, and the server issues a one-time-password
543 challenge conforming to RFC1938, \fIfetchmail\fR will use your
544 password as a pass phrase to generate the required response. This
545 avoids sending secrets over the net unencrypted.
547 Compuserve's RPA authentication (similar to APOP) is supported. If
548 you are using POP3, and the RPA code has been compiled into your
549 binary, and you query a server in the Compuserve csi.com domain,
550 \fIfetchmail\fR will try to perform an RPA pass-phrase authentication
551 instead of sending over the password en clair.
553 If you are using IPsec, the -T (--netsec) option can be used to pass
554 an IP security request to be used when outgoing IP connections are
555 initialized. You can also do this using the `netsec' server option
556 in the .fetchmailrc file. In either case, the option value is a
557 string in the format accepted by the net_security_strtorequest()
558 function of the inet6_apps library.
567 in daemon mode. You must specify a numeric argument which is a
568 polling interval in seconds.
572 puts itself in background and runs forever, querying each specified
573 host and then sleeping for the given polling interval.
579 will, therefore, poll all the hosts described in your
581 file (except those explicitly excluded with the `skip' verb) once
582 every fifteen minutes.
584 It is possible to set a polling interval
587 file by saying `set daemon <interval>', where <interval> is an
588 integer number of seconds. If you do this, fetchmail will always
589 start in daemon mode unless you override it with the command-line
590 option --daemon 0 or -d0.
592 Only one daemon process is permitted per user; in daemon mode,
594 makes a per-user lockfile to guarantee this.
596 Normally, calling fetchmail with a daemon in the background sends a
597 wakeup signal to the daemon, forcing it to poll mailservers
598 immediately. (The wakeup signal is SIGHUP if fetchmail is running as
599 root, SIGUSR1 otherwise.)
603 will kill a running daemon process instead of waking it up (if there
606 notifies you). If the --quit option is the only command-line option,
607 that's all there is to it.
609 The quit option may also be mixed with other command-line options; its
610 effect is to kill any running daemon before doing what the other
611 options specify in combination with the rc file.
617 option (keyword: timeout) allows you to set a server-nonresponse
618 timeout in seconds. If a mailserver does not send a greeting message
619 or respond to commands for the given number of seconds,
620 \fIfetchmail\fR will hang up on it. Without such a timeout
621 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
622 down host. This would be particularly annoying for a \fIfetchmail\fR
623 running in background. There is a default timeout which fetchmail -V
630 option (keyword: set logfile) allows you to redirect status messages
631 emitted while detached into a specified logfile (follow the
632 option with the logfile name). The logfile is opened for append, so
633 previous messages aren't deleted. This is primarily useful for
634 debugging configurations.
638 option (keyword: set syslog) allows you to redirect status and error
639 messages emitted to the
641 system daemon if available.
642 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
643 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
644 This option is intended for logging status and error messages which
645 indicate the status of the daemon and the results while fetching mail
647 Error messages for command line options and parsing the \fI.fetchmailrc\fR
648 file are still written to stderr, or the specified log file if the
651 option turns off use of
653 assuming it's turned on in the
663 or --nodetach option suppresses backgrounding and detachment of the
664 daemon process from its control terminal. This is primarily useful
665 for debugging. Note that this also causes the logfile option to be
666 ignored (though perhaps it shouldn't).
668 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
669 transient errors (such as DNS failures or sendmail delivery refusals)
670 may force the fetchall option on for the duration of the next polling
671 cycle. This is a robustness feature. It means that if a message is
672 fetched (and thus marked seen by the mailserver) but not delivered
673 locally due to some transient error, it will be re-fetched during the
674 next poll cycle. (The IMAP logic doesn't delete messages until
675 they're delivered, so this problem does not arise.)
677 .SH ADMINISTRATIVE OPTIONS
681 option (keyword: set postmaster) specifies the last-resort username to
682 which multidrop mail is to be forwarded if no matching local recipient
683 can be found. Normally this is just the user who invoked fetchmail.
684 If the invoking user is root, then the default of this option is
685 the user `postmaster'.
689 option (keyword: set invisible) tries to make fetchmail invisible.
690 Normally, fetchmail behaves like any other MTA would -- it generates a
691 Received header into each message describing its place in the chain of
692 transmission, and tells the MTA it forwards to that the mail came from
693 the machine fetchmail itself is running on. If the invisible option
694 is on, the Received header is suppressed and fetchmail tries to spoof
695 the MTA it forwards to into thinking it came directly from the
698 .SH RETRIEVAL FAILURE MODES
699 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
700 bulletproof. In normal operation forwarding to port 25, no message is
701 ever deleted (or even marked for deletion) on the host until the SMTP
702 listener on the client has acknowledged to \fIfetchmail\fR that the
703 message has been accepted for delivery. When forwarding to an MDA,
704 however, there is more possibility of error (because there's no way
705 for fetchmail to get a reliable positive acknowledgement from the MDA).
707 The normal mode of \fIfetchmail\fR is to try to download only `new'
708 messages, leaving untouched (and undeleted) messages you have already
709 read directly on the server (or fetched with a previous \fIfetchmail
710 --keep\fR). But you may find that messages you've already read on the
711 server are being fetched (and deleted) even when you don't specify
712 --all. There are several reasons this can happen.
714 One could be that you're using POP2. The POP2 protocol includes no
715 representation of `new' or `old' state in messages, so \fIfetchmail\fR
716 must treat all messages as new all the time. But POP2 is obsolete, so
719 Under POP3, blame RFC1725. That version of the POP3 protocol
720 specification removed the LAST command, and some POP servers follow it
721 (you can verify this by invoking \fIfetchmail -v\fR to the mailserver
722 and watching the response to LAST early in the query). The
723 \fIfetchmail\fR code tries to compensate by using POP3's UID feature,
724 storing the identifiers of messages seen in each session until the
725 next session, in the \fI.fetchids\fR file. But this doesn't track
726 messages seen with other clients, or read directly with a mailer on
727 the host but not deleted afterward. A better solution would be to
730 Another potential POP3 problem might be servers that insert messages
731 in the middle of mailboxes (some VMS implementations of mail are
732 rumored to do this). The \fIfetchmail\fR code assumes that new
733 messages are appended to the end of the mailbox; when this is not true
734 it may treat some old messages as new and vice versa. The only
735 real fix for this problem is to switch to IMAP.
737 The IMAP code uses the presence or absence of the server flag \eSeen
738 to decide whether or not a message is new. Under Unix, it counts on
739 your IMAP server to notice the BSD-style Status flags set by mail user
740 agents and set the \eSeen flag from them when appropriate. All Unix
741 IMAP servers we know of do this, though it's not specified by the IMAP
742 RFCs. If you ever trip over a server that doesn't, the symptom will
743 be that messages you have already read on your host will look new to
744 the server. In this (unlikely) case, only messages you fetched with
745 \fIfetchmail --keep\fR will be both undeleted and marked old.
747 In ETRN mode, \fIfetchmail\fR does not actually retrieve messages;
748 instead, it asks the server's SMTP listener to start a queue flush
749 to the client via SMTP. Therefore it sends only undelivered messages.
752 Many SMTP listeners allow administrators to set up `spam filters' that
753 block unsolicited email from specified domains. A MAIL FROM line that
754 triggers this feature will elicit an SMTP response which
755 (unfortunately) varies according to the listener.
759 return an error code of 571. This return value
760 is blessed by RFC1893 as "Delivery not authorized, message refused".
762 According to current drafts of the replacement for RFC821, the correct
763 thing to return in this situation is 550 "Requested action not taken:
764 mailbox unavailable" (the draft adds "[E.g., mailbox not found, no
765 access, or command rejected for policy reasons].").
769 MTA returns 501 "Syntax error in parameters or arguments", but will
774 code recognizes and discards the message on any of a list of responses
775 that defaults to [571, 550, 501] but can be set with the `antispam'
778 circumstance under which fetchmail ever discards mail.
782 is fetching from an IMAP server, the antispam response will be detected and
783 the message rejected immediately after the headers have been fetched,
784 without reading the message body. Thus, you won't pay for downloading
787 .SH THE RUN CONTROL FILE
788 The preferred way to set up fetchmail is to write a
789 \&\fI.fetchmailrc\fR file in your home directory. When there is a
790 conflict between the command-line arguments and the arguments in this
791 file, the command-line arguments take precedence.
793 To protect the security of your passwords, when --version is not on
794 your \fI~/.fetchmailrc\fR may not have more than 0600 (u=rw,g=,o=) permissions;
796 will complain and exit otherwise.
798 You may read the \fI.fetchmailrc\fR file as a list of commands to
801 is called with no arguments.
802 .SS Run Control Syntax
804 Comments begin with a '#' and extend through the end of the line.
805 Otherwise the file consists of a series of server entries or global
806 option statements in a free-format, token-oriented syntax.
808 There are four kinds of tokens: grammar keywords, numbers
809 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
810 A quoted string is bounded by double quotes and may contain
811 whitespace (and quoted digits are treated as a string). An unquoted
812 string is any whitespace-delimited token that is neither numeric, string
813 quoted nor contains the special characters `,', `;', `:', or `='.
815 Any amount of whitespace separates tokens in server entries, but is
816 otherwise ignored. You may use standard C-style escapes (\en, \et,
817 \eb, octal, and hex) to embed non-printable characters or string
818 delimiters in strings.
820 Each server entry consists of one of the keywords `poll' or `skip',
821 followed by a server name, followed by server options, followed by any
822 number of user descriptions. Note: the most common cause of syntax
823 errors is mixing up user and server options.
825 For backward compatibility, the word `server' is a synonym for `poll'.
827 You can use the noise keywords `and', `with',
828 \&`has', `wants', and `options' anywhere in an entry to make
829 it resemble English. They're ignored, but but can make entries much
830 easier to read at a glance. The punctuation characters ':', ';' and
831 \&',' are also ignored.
834 The `poll' verb tells fetchmail to query this host when it is run with
835 no arguments. The `skip' verb tells
837 not to poll this host unless it is explicitly named on the command
838 line. (The `skip' verb allows you to experiment with test entries
839 safely, or easily disable entries for hosts that are temporarily down.)
841 .SS Keyword/Option Summary
842 Here are the legal server options. Keyword suffixes enclosed in
843 square brackets are optional. Those corresponding to command-line
844 options are followed by `-' and the appropriate option letter.
851 Specify DNS name of mailserver, overriding poll name
854 Specify protocol (case insensitive):
855 POP2, POP3, IMAP, IMAP-K4, IMAP-GSS, APOP, KPOP
858 Specify TCP/IP service port
861 Set preauthentication type (default `password')
864 Server inactivity timout in seconds (default 300)
867 Specify envelope-address header name
870 Disable looking for envelope address
873 Qmail virtual domain prefix to remove from user name
876 Specify alternate DNS names of mailserver
879 specify IP interface(s) that must be up for server poll to take place
882 Specify IP address to monitor for activity
885 Enable DNS lookup for multidrop (default)
888 Disable DNS lookup for multidrop
891 Do comparison by IP address for multidrop
894 Do comparison by name for multidrop (default)
897 Force POP3 to use client-side UIDLs
900 Turn off POP3 use of client-side UIDLs (default)
904 Here are the legal user options:
912 (local user name if name followed by `here')
915 Connect local and remote user names
918 Connect local and remote user names
921 Specify remote account password
924 Specify remote folder to query
927 Specify smtp host(s) to forward to
930 Specify the domain to be put in RCPT TO lines
933 Specify what SMTP returns are interpreted as spam-policy blocks
936 Specify MDA for local delivery
939 Command to be executed before each connection
942 Command to be executed after each connection
945 Don't delete seen messages from server
948 Flush all seen messages before querying
951 Fetch all messages whether seen or not
954 Rewrite destination addresses for reply (default)
957 Strip carriage returns from ends of lines
960 Force carriage returns at ends of lines
963 Force BODY=8BITMIME to ESMTP listener
966 Strip Status and X-Mozilla-Status lines out of incoming mail
969 Convert quoted-printable to 8-bit in MIME messages
972 Delete seen messages from server (default)
975 Don't flush all seen messages before querying (default)
978 Retrieve only new messages (default)
981 Don't rewrite headers
984 Don't strip carriage returns (default)
987 Don't force carriage returns at EOL (default)
990 Don't force BODY=8BITMIME to ESMTP listener (default)
993 Don't drop Status headers (default)
996 Don't convert quoted-printable to 8-bit in MIME messages (default)
999 Set message size limit
1002 Max # messages to fetch in single connect
1005 Max # messages to forward in single connect
1008 Perform an expunge on every #th message (IMAP only)
1011 Do error logging through syslog(3).
1014 Turn off error logging through syslog(3).
1018 Remember that all user options must \fIfollow\fR all server options.
1020 In the .fetchmailrc file, the `envelope' string argument may be
1021 preceded by a whitespace-separated number. This number, if specified,
1022 is the number of such headers to skip (that is, an argument of 1
1023 selects the second header of the given type). This is sometime useful
1024 for ignoring bogus Received headers created by an ISP's local delivery
1026 .SS Keywords Not Corresponding To Option Switches
1028 The `folder' and `smtphost' options (unlike their command-line
1029 equivalents) can take a space- or comma-separated list of names
1032 All options correspond to the obvious command-line arguments, except
1033 the following: `via', `interval', `aka', `is', `to', `dns'/`no dns',
1034 `checkalias'/`no checkalias',
1035 \&`password', \&`preconnect', \&`postconnect', `localdomains',
1036 \&`stripcr'/`no stripcr', \&`forcecr'/`no forcecr', `pass8bits'/`no
1037 pass8bits' `dropstatus/no dropstatus', `mimedecode/no mimedecode',
1040 The `via' option is for use with ssh, or if you want to have more
1041 than one configuration pointing at the same site. If it is present,
1042 the string argument will be taken as the actual DNS name of the
1043 mailserver host to query.
1044 This will override the argument of poll, which can then simply be a
1045 distinct label for the configuration (e.g. what you would give on the
1046 command line to explicitly query this host).
1047 If the `via' name is `localhost', the poll name will also still be
1048 used as a possible match in multidrop mode; otherwise the `via' name
1049 will be used instead and the poll name will be purely a label.
1051 The `interval' option (which takes a numeric argument) allows you to poll a
1052 server less frequently than the basic poll interval. If you say
1053 \&`interval N' the server this option is attached to will only be
1054 queried every N poll intervals.
1056 The `is' or `to' keywords associate the following local (client)
1057 name(s) (or server-name to client-name mappings separated by =) with
1058 the mailserver user name in the entry. If an is/to list has `*' as
1059 its last name, unrecognized names are simply passed through.
1061 A single local name can be used to support redirecting your mail when
1062 your username on the client machine is different from your name on the
1063 mailserver. When there is only a single local name, mail is forwarded
1064 to that local username regardless of the message's Received, To, Cc,
1065 and Bcc headers. In this case
1067 never does DNS lookups.
1069 When there is more than one local name (or name mapping) the
1070 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1071 headers of retrieved mail (this is `multidrop mode'). It looks for
1072 addresses with hostname parts that match your poll name or your `via',
1073 `aka' or `localdomains' options, and usually also for hostname parts
1074 which DNS tells it are aliases of the mailserver. See the discussion
1075 of `dns', `checkalias', `localdomains', and `aka' for details on how
1076 matching addresses are handled.
1078 If \fIfetchmail\fR cannot match any mailserver usernames or
1079 localdomain addresses, the default recipient is the value of the
1080 `postmaster' global option if that has been set; otherwise it's the
1081 calling user (as set by the USER or LOGNAME variable in the
1084 The `dns' option (normally on) controls the way addresses from
1085 multidrop mailboxes are checked. On, it enables logic to check each
1086 host address that doesn't match an `aka' or `localdomains' declaration
1087 by looking it up with DNS. When a mailserver username is recognized
1088 attached to a matching hostname part, its local mapping is added to
1089 the list of local recipients.
1091 The `checkalias' option (normally off) extends the lookups performed
1092 by the `dns' keyword in multidrop mode, providing a way to cope with
1093 remote MTAs that identify themselves using their canonical name, while
1094 they're polled using an alias.
1095 When such a server is polled, checks to extract the envelope address
1098 reverts to delivery using the To/Cc/Bcc headers (See below
1099 `Header vs. Envelope addresses').
1100 Specifying this option instructs
1102 to retrieve all the IP addresses associated with both the poll name
1103 and the name used by the remote MTA and to do a comparison of the IP
1104 addresses. This comes in handy in situations where the remote server
1105 undergoes frequent canonical name changes, that would otherwise
1106 require modifications to the rcfile. `checkalias' has no effect if
1107 `no dns' is specified in the rcfile.
1109 The `aka' option is for use with multidrop mailboxes. It allows you
1110 to pre-declare a list of DNS aliases for a server. This is an
1111 optimization hack that allows you to trade space for speed. When
1113 while processing a multidrop mailbox, grovels through message headers
1114 looking for names of the mailserver, pre-declaring common ones can
1115 save it from having to do DNS lookups.
1117 The `localdomains' option allows you to declare a list of domains
1118 which fetchmail should consider local. When fetchmail is parsing
1119 address lines in multidrop modes, and a trailing segment of a host
1120 name matches a declared local domain, that address is passed through
1121 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1124 If you are using `localdomains', you may also need to specify \&`no
1125 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1126 an envelope address from the Received line or X-Envelope-To header or
1127 whatever header has been previously set by `envelope'. If you set `no
1128 envelope' in the defaults entry it is possible to undo that in
1129 individual entries by using `envelope <string>'. As a special case,
1130 \&`envelope "Received"' restores the default parsing of
1133 The \fBpassword\fR option requires a string argument, which is the password
1134 to be used with the entry's server.
1136 The `preconnect' keyword allows you to specify a shell command to be
1137 executed just before each time
1139 establishes a mailserver connection. This may be useful if you are
1140 attempting to set up secure POP connections with the aid of
1142 If the command returns a nonzero status, the poll of that mailserver
1145 Similarly, the `postconnect' keyword similarly allows you to specify a
1146 shell command to be executed just after each time a mailserver
1147 connection is taken down.
1149 The `forcecr' option controls whether lines terminated by LF only are
1150 given CRLF termination before forwarding. Strictly speaking RFC821
1151 requires this, but few MTAs enforce the requirement it so this option
1152 is normally off (only one such MTA, qmail, is in significant use at
1155 The `stripcr' option controls whether carriage returns are stripped
1156 out of retrieved mail before it is forwarded. It is normally not
1157 necessary to set this, because it defaults to `on' (CR stripping
1158 enabled) when there is an MDA declared but `off' (CR stripping
1159 disabled) when forwarding is via SMTP. If `stripcr' and `forcecr' are
1160 both on, `stripcr' will override.
1162 The `pass8bits' option exists to cope with Microsoft mail programs that
1163 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1164 this option off (the default) and such a header present,
1166 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1167 messages actually using 8-bit ISO or KOI-8 character sets, which will
1168 be garbled by having the high bits of all characters stripped. If
1169 \&`pass8bits' is on,
1171 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1172 the listener is 8-bit-clean (as all the major ones now are) the right
1173 thing will probably result.
1175 The `dropstatus' option controls whether nonempty Status and
1176 X-Mozilla-Status lines are retained in fetched mail (the default) or
1177 discarded. Retaining them allows your MUA to see what messages (if
1178 any) were marked seen on the server. On the other hand, it can
1179 confuse some new-mail notifiers, which assume that anything with a
1180 Status line in it has been seen. (Note: the empty Status lines
1181 inserted by some buggy POP servers are unconditionally discarded.)
1183 The `mimedecode' option controls whether MIME messages using the
1184 quoted-printable encoding are automatically converted into pure
1185 8-bit data. If you are delivering mail to an ESMTP-capable,
1186 8-bit-clean listener (that includes all of the major programs
1187 like sendmail), then this will automatically convert quoted-printable
1188 message headers and data into 8-bit data, making it easier to
1189 understand when reading mail. If your e-mail programs know how to
1190 deal with MIME messages, then this option is not needed.
1192 .SS Miscellaneous Run Control Options
1193 The words `here' and `there' have useful English-like
1194 significance. Normally `user eric is esr' would mean that
1195 mail for the remote user `eric' is to be delivered to `esr',
1196 but you can make this clearer by saying `user eric there is esr here',
1197 or reverse it by saying `user esr here is eric there'
1199 Legal protocol identifiers for use with the `protocol' keyword are:
1205 imap-k4 (or IMAP-K4)
1206 imap-gss (or IMAP-GSS)
1211 Legal authentication types are `password' or `kerberos'. The former
1212 specifies authentication by normal transmission of a password (the
1213 password may be plaintext or subject to protocol-specific encryption
1214 as in APOP); the second tells \fIfetchmail\fR to try to get a Kerberos
1215 ticket at the start of each query instead, and send an arbitrary
1216 string as the password.
1218 Specifying `kpop' sets POP3 protocol over port 1109 with Kerberos V4
1219 preauthentication. These defaults may be overridden by later options.
1221 There are currently three global option statements; `set logfile'
1222 followed by a string sets the same global specified by --logfile. A
1223 command-line --logfile option will override this. Also, `set daemon'
1224 sets the poll interval as --daemon does. This can be overridden by
1225 a command-line --daemon option; in particular --daemon 0 can be used
1226 to force foreground operation. Finally, `set syslog' sends log
1227 messages to syslogd(8).
1229 .SH INTERACTION WITH RFC 822
1230 When trying to detertmine the originating address of a message,
1231 fetchmail looks through headers in the following order:
1241 The originating address is used for logging, and to set the MAIL FROM
1242 address when forwarding to SMTP. This order is intended to cope
1243 gracefully with receiving mailing list messages in multidrop mode. The
1244 intent is that if a local address doesn't exist, the bounce message
1245 won't be returned blindly to the author or to the list itself, but
1246 rather to the list manager (which is less annoying).
1248 In multidrop mode, destination headers are processed as follows:
1249 First, fetchmail looks for the Received: header (or whichever one is
1250 specified by the `envelope' option) to determine the local
1251 recipient adress. If the mail is addressed to more than one recipient,
1252 the Received line won't contain any information regarding recipient adresses.
1254 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1255 lines. If they exists, they should contain the final recipients and
1256 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1257 lines doesn't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1258 looked for. (The presence of a Resent-To: is taken to impluy that the
1259 person referred by the To: address has already received the original
1262 .SH CONFIGURATION EXAMPLES
1266 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1272 poll pop.provider.net protocol pop3 username jsmith password secret1
1275 Or, using some abbreviations:
1278 poll pop.provider.net proto pop3 user jsmith password secret1
1281 Multiple servers may be listed:
1284 poll pop.provider.net proto pop3 user jsmith pass secret1
1285 poll other.provider.net proto pop2 user John.Smith pass My^Hat
1288 Here's a version of those two with more whitespace and some noise words:
1291 poll pop.provider.net proto pop3
1292 user jsmith, with password secret1, is jsmith here;
1293 poll other.provider.net proto pop2:
1294 user John.Smith, with password My^Hat, is John.Smith here;
1297 This version is much easier to read and doesn't cost significantly
1298 more (parsing is done only once, at startup time).
1301 If you need to include whitespace in a parameter string, enclose the
1302 string in double quotes. Thus:
1305 poll mail.provider.net with proto pop3:
1306 user jsmith there has password "u can't krak this"
1307 is jws here and wants mda "/bin/mail"
1310 You may have an initial server description headed by the keyword
1311 `defaults' instead of `poll' followed by a name. Such a record
1312 is interpreted as defaults for all queries to use. It may be overwritten
1313 by individual server descriptions. So, you could write:
1318 poll pop.provider.net
1320 poll mail.provider.net
1321 user jjsmith there has password secret2
1324 It's possible to specify more than one user per server (this is only
1325 likely to be useful when running fetchmail in daemon mode as root).
1326 The `user' keyword leads off a user description, and every user specification
1327 in a multi-user entry must include it. Here's an example:
1330 poll pop.provider.net proto pop3 port 3111
1331 user jsmith with pass secret1 is smith here
1332 user jones with pass secret2 is jjones here
1335 This associates the local username `smith' with the pop.provider.net
1336 username `jsmith' and the local username `jjones' with the
1337 pop.provider.net username `jones'.
1339 Here's what a simple retrieval configuration for a multi-drop mailbox
1343 poll pop.provider.net:
1344 user maildrop with pass secret1 to golux hurkle=happy snark here
1347 This says that the mailbox of account `maildrop' on the server is a
1348 multi-drop box, and that messages in it should be parsed for the
1349 server user names `golux', `hurkle', and `snark'. It further
1350 specifies that `golux' and `snark' have the same name on the
1351 client as on the server, but mail for server user `hurkle' should be
1352 delivered to client user `happy'.
1354 Here's an example of another kind of multidrop connection:
1357 poll pop.provider.net localdomains loonytoons.org:
1358 user maildrop with pass secret1 to esr * here
1361 This also says that the mailbox of account `maildrop' on the server is
1362 a multi-drop box. It tells fetchmail that any address in the
1363 loonytoons.org domain (including subdomain addresses like
1364 `joe@daffy.loonytoons.org') should be passed through to the local SMTP
1365 listener without modification. Be careful of mail loops if you do this!
1367 Here's an example configuration using ssh. The queries go through an
1368 ssh connecting local port 1234 to port 110 on mailhost.net; the
1369 preconnect command sets up the ssh.
1372 poll mailhost.net via localhost port 1234 with proto pop3:
1373 preconnect "ssh -f -L 1234:mailhost.net:110
1374 mailhost.net sleep 20 </dev/null >/dev/null";
1377 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
1378 Use the multiple-local-recipients feature with caution -- it can bite.
1379 Also note that all multidrop features are ineffective in ETRN mode.
1381 .SS Header vs. Envelope addresses
1382 The fundamental problem is that by having your mailserver toss several
1383 peoples' mail in a single maildrop box, you may have thrown away
1384 potentially vital information about who each piece of mail was
1385 actually addressed to (the `envelope address', as opposed to the
1386 header addresses in the RFC822 To/Cc/Bcc headers). This `envelope
1387 address' is the address you need in order to reroute mail properly.
1391 can deduce the envelope address. If the mailserver MTA is
1393 and the item of mail had just one recipient, the MTA will have written
1394 a `by/for' clause that gives the envelope addressee into its Received
1395 header. But this doesn't work reliably for other MTAs, nor if there is
1396 more than one recipient. By default, \fIfetchmail\fR looks for
1397 envelope addresses in these lines; you can restore this default with
1398 -E "Received" or \&`envelope Received'.
1400 Alternatively, some SMTP listeners and/or mail servers insert a header
1401 in each message containing a copy of the envelope addresses. This
1402 header (when it exists) is often `X-Envelope-To'. Fetchmail's
1403 assumption about this can be changed with the -E or `envelope' option.
1404 Note that writing an envelope header of this kind exposes the names of
1405 recipients (including blind-copy recopients) to all receivers of the
1406 messages; it is therefore regarded by some administrators as a
1407 security/privacy problem.
1409 A slight variation of the `X-Envelope-To' header is the `Delivered-To' put
1410 by qmail to avoid mail loops. It will probably prefix the user name with a
1411 string that normally matches the user's domain. To remove this prefix you
1412 can use the -Q or `qvirtual' option.
1414 Sometimes, unfortunately, neither of these methods works. When they
1415 all fail, fetchmail must fall back on the contents of To/Cc/Bcc
1416 headers to try to determine recipient addressees -- and these are not
1417 reliable. In particular, mailing-list software often ships mail with
1418 only the list broadcast address in the To header.
1422 cannot deduce a recipient address that is local, and the intended
1423 recipient address was anyone other than fetchmail's invoking user,
1424 mail will get lost. This is what makes the multidrop feature risky.
1426 A related problem is that when you blind-copy a mail message, the Bcc
1427 information is carried \fIonly\fR as envelope address (it's not put
1428 in the headers fetchmail can see unless there is an X-Envelope
1429 header). Thus, blind-copying to someone who gets mail over a
1430 fetchmail link will fail unless the the mailserver host routinely
1431 writes X-Envelope or an equivalent header into messages in your maildrop.
1433 .SS Good Ways To Use Multidrop Mailboxes
1434 Multiple local names can be used to administer a mailing list from the
1435 client side of a \fIfetchmail\fR collection. Suppose your name is
1436 \&`esr', and you want to both pick up your own mail and maintain a mailing
1437 list called (say) "fetchmail-friends", and you want to keep the alias
1438 list on your client machine.
1440 On your server, you can alias \&`fetchmail-friends' to `esr'; then, in
1441 your \fI.fetchmailrc\fR, declare \&`to esr fetchmail-friends here'.
1442 Then, when mail including `fetchmail-friends' as a local address
1443 gets fetched, the list name will be appended to the list of
1444 recipients your SMTP listener sees. Therefore it will undergo alias
1445 expansion locally. Be sure to include `esr' in the local alias
1446 expansion of fetchmail-friends, or you'll never see mail sent only to
1447 the list. Also be sure that your listener has the "me-too" option set
1448 (sendmail's -oXm command-line option or OXm declaration) so your name
1449 isn't removed from alias expansions in messages you send.
1451 This trick is not without its problems, however. You'll begin to see
1452 this when a message comes in that is addressed only to a mailing list
1453 you do \fInot\fR have declared as a local name. Each such message
1454 will feature an `X-Fetchmail-Warning' header which is generated
1455 because fetchmail cannot find a valid local name in the recipient
1456 addresses. Such messages default (as was described above) to being
1457 sent to the local user running
1459 but the program has no way to know that that's actually the right thing.
1461 .SS Bad Ways To Abuse Multidrop Mailboxes
1462 Multidrop mailboxes and
1464 serving multiple users in daemon mode do not mix. The problem, again, is
1465 mail from mailing lists, which typically does not have an individual
1466 recipient address on it. Unless
1468 can deduce an envelope address, such mail will only go to the account
1469 running fetchmail (probably root). Also, blind-copied users are very
1470 likely never to see their mail at all.
1472 If you're tempted to use
1474 to retrieve mail for multiple users from a single mail drop via POP or
1475 IMAP, think again (and reread the section on header and envelope
1476 addresses above). It would be smarter to just let the mail sit in the
1477 mailserver's queue and use fetchmail's ETRN mode to trigger SMTP sends
1478 periodically (of course, this means you have to poll more frequently
1479 than the mailserver's expiry period). If you can't arrange this, try
1480 setting up a UUCP feed.
1482 If you absolutely \fImust\fR use multidrop for this purpose, make sure
1483 your mailserver writes an envelope-address header that fetchmail can
1484 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
1487 .SS Speeding Up Multidrop Checking
1488 Normally, when multiple user are declared
1490 extracts recipient addresses as described above and checks each host
1491 part with DNS to see if it's an alias of the mailserver. If so, the
1492 name mappings described in the to ... here declaration are done and
1493 the mail locally delivered.
1495 This is the safest but also slowest method. To speed it up,
1496 pre-declare mailserver aliases with `aka'; these are checked before
1497 DNS lookups are done. If you're certain your aka list contains
1499 DNS aliases of the mailserver (and all MX names pointing at it)
1500 you can declare `no dns' to suppress DNS lookups entirely and
1501 \fIonly\fR match against the aka list.
1504 To facilitate the use of
1506 in shell scripts, an exit code is returned to give an indication
1507 of what occurred during a given connection.
1509 The exit codes returned by
1513 One or more messages were successfully retrieved.
1515 There was no mail awaiting retrieval. (There may have been old mail still
1516 on the server but not selected for retrieval.)
1518 An error was encountered when attempting to open a socket for the POP
1519 connection. If you don't know what a socket is, don't worry about it --
1520 just treat this as an 'unrecoverable error'.
1522 The user authentication step failed. This usually means that a bad
1523 user-id, password, or APOP id was specified.
1525 Some sort of fatal protocol error was detected.
1527 There was a syntax error in the arguments to
1530 The run control file had bad permissions.
1532 There was an error condition reported by the server. Can also
1535 timed out while waiting for the server.
1537 Client-side exclusion error. This means
1539 either found another copy of itself already running, or failed in such
1540 a way that it isn't sure whether another copy is running.
1542 The user authentication step failed because the server responded "lock
1543 busy". Try again after a brief pause! This error is not implemented
1544 for all protocols, nor for all servers. If not implemented for your
1545 server, "3" will be returned instead, see above. May be returned when
1546 talking to qpopper or other servers that can respond with "lock busy"
1547 or some similar text containing the word "lock".
1551 run failed while trying to do an SMTP port open or transaction.
1553 Fatal DNS error. Fetchmail encountered an error while performing
1554 a DNS lookup at startup and could not proceed.
1556 Internal error. You should see a message on standard error with
1561 queries more than one host, return status is 0 if \fIany\fR query
1562 successfully retrieved mail. Otherwise the returned error status is
1563 that of the last host queried.
1566 Eric S. Raymond <esr@snark.thyrsus.com>.
1567 This program is descended from and replaces
1569 by Carl Harris <ceharris@mal.com>; the internals are quite different,
1570 but some of its interface design is directly traceable to that
1576 default run control file
1579 default location of file associating hosts with last message IDs seen
1580 (used only with newer RFC1725-compliant POP3 servers supporting the
1584 your FTP run control file, which (if present) will be searched for
1585 passwords as a last resort before prompting for one interactively.
1588 lock file to help prevent concurrent runs (non-root mode).
1590 /var/run/fetchmail.pid
1591 lock file to help prevent concurrent runs (root mode, Linux systems).
1594 lock file to help prevent concurrent runs (root mode, systems without /var/run).
1597 For correct initialization,
1599 requires either that both the USER and HOME environment variables are
1600 correctly set, or that \fBgetpwuid\fR(3) be able to retrieve a password
1601 entry from your user ID.
1606 daemon is running as root, SIGHUP wakes it up from its sleep phase and
1607 forces a poll of all non-skipped servers (this is in accordance with
1608 the usual conventions for system daemons).
1612 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
1613 so SIGHUP due to logout can retain the default action of killing it).
1617 in foreground while a background fetchmail is running will do
1618 whichever of these is appropriate to wake it up.
1620 .SH BUGS AND KNOWN PROBLEMS
1621 Enabling the `mimedecode' option (which defaults to off) may render
1622 invalid any PGP signatures attached to mail with quoted-printable headers.
1623 This bug will be fixed in a future version.
1625 The RFC822 address parser used in multidrop mode chokes on some
1626 @-addresses that are technically legal but bizarre. Strange uses of
1627 quoting and embedded comments are likely to confuse it.
1629 Use of any of the supported protocols other than POP3 with OTP or RPA, APOP,
1630 KPOP, IMAP-K4, IMAP-GSS, or ETRN requires that the program send unencrypted
1631 passwords over the TCP/IP connection to the mailserver. This creates
1632 a risk that name/password pairs might be snaffled with a packet
1633 sniffer or more sophisticated monitoring software. Under Linux, the
1634 --interface option can be used to restrict polling to availability of
1635 a specific interface device with a specific local IP address, but
1636 snooping is still possible if (a) either host has a network device
1637 that can be opened in promiscuous mode, or (b) the intervening network
1640 Use of the %F or %T escapes in an mda option could open a security
1641 hole, because they pass text manipulable by an attacker to a shell
1642 command. Potential shell characters are replaced by `_' before
1643 execution. The hole is further reduced by the fact that fetchmail
1644 temporarily discards any suid privileges it may have while running the
1645 MDA. For maximum safety, however, don't use an mda command containing
1646 %F or %T when fetchmail is run from the root account itself.
1648 Send comments, bug reports, gripes, and the like to Eric S. Raymond
1649 <esr@thyrsus.com>. An HTML FAQ is available at the fetchmail home
1650 page; surf to http://www.tuxedo.org/~esr/fetchmail or do a WWW search
1651 for pages with `fetchmail' in their titles.
1654 elm(1), mail(1), sendmail(8), popd(8), imapd(8)
1655 .SH APPLICABLE STANDARDS
1658 RFC 821, RFC 1869, RFC 1652, RFC 1870, RFC1983, RFC 1985
1667 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1939
1670 RFC 1460, RFC 1725, RFC 1939
1679 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061
projects / ~andy / fetchmail / blob