   (This document was generated from fetchmail-FAQ.html)

   Back to Fetchmail Home Page To Site Map $Date: 1998/03/24 00:04:29 $
     _________________________________________________________________
   
                  Frequently Asked Questions About Fetchmail
                                       
   Before reporting any bug, please read G3 for advice on how to include
   diagnostic information that will get your bug fixed as quickly as
   possible.
   
   If you have a question or answer you think ought to be added to this
   FAQ list, mail it to fetchmail's maintainer, Eric S. Raymond, at
   esr@snark.thyrsus.com.
   
                              General questions:
                                       
   G1. What is fetchmail and why should I bother?
   G2. Where do I find the latest FAQ and fetchmail sources?
   G3. I think I've found a bug. Will you fix it?
   G4. I have this idea for a neat feature. Will you add it?
   G5. Is there a mailing list for exchanging tips?
   G6. So, what's this I hear about a fetchmail paper?
   G7. What is the best server to use with fetchmail?
   G8. How can I avoid sending my password en clair?
   G9. Is any special configuration needed to use a dynamic IP address?
   G10. Is any special configuration needed to use firewalls?
   
                             Build-time problems:
                                       
   B1. Lex bombs out while building the fetchmail lexer.
   B2. I get link failures when I try to build fetchmail.
   
                Fetchmail configuration file grammar questions:
                                       
   F1. Why does my old .fetchmailrc no longer work?
   F2. The .fetchmailrc parser won't accept my all-numeric user name.
   F3. The .fetchmailrc parser won't accept my host or username beginning
   with `no'.
   F4. I'm migrating from popclient. How do I need to modify my .poprc?
   F5. I'm getting a `parse error' message I don't understand.
   
                           Configuration questions:
                                       
   C1. Why do I need a .fetchmailrc when running as root on my own
   machine?
   C2. How can I arrange for a fetchmail daemon to get killed when I log
   out?
   C3. How do I know what interface and address to use with --interface?
   C4. How can I get fetchmail to work with ssh?
   C5. How can I set up support for sendmail's anti-spam 571 response?
   C6. How can I do automatic startup/shutdown of fetchmail when I may
   have multiple login sessions going?
   
             How to make fetchmail play nice with other software:
                                       
   T1. How can I use fetchmail with sendmail?
   T2. How can I use fetchmail with qmail?
   T3. How can I use fetchmail with exim?
   T4. How can I use fetchmail with smail?
   T5. How can I use fetchmail with SCO's MMDF?
   T6. How can I use fetchmail with Lotus Notes?
   T7. How can I use fetchmail with Microsoft Exchange?
   T8. How can I use fetchmail with Compuserve RPA?
   T9. How can I use fetchmail with HP OpenMail?
   T11. How can I use fetchmail with IPv6 and IPsec?
   
                             Runtime fatal errors:
                                       
   R1. Fetchmail's initial gethostbyname call fails on my host.
   R2. Fetchmail isn't working, and -v shows `SMTP connect failed'
   messages.
   R3. When I try to configure an MDA, fetchmail doesn't work.
   R4. Fetchmail dumps core when given an invalid rc file.
   R5. Fetchmail dumps core in -V mode, but operates normally otherwise.
   R6. Fetchmail dumps core when I use a .netrc file but works otherwise.
   R7. Running fetchmail in daemon mode doesn't work.
   R8. Fetchmail hangs when used with pppd.
   
                               Disappearing mail
                                       
   D1. I think I've set up fetchmail correctly, but I'm not getting any
   mail.
   D2. All my mail seems to disappear after an interrupt.
   D3. Mail that was being fetched when I interrupted my fetchmail seems
   to have been vanished.
   
                           Multidrop-mode problems:
                                       
   M1. I've declared local names, but all my multidrop mail is going to
   root anyway.
   M2. I can't seem to get fetchmail to route to a local domain properly.
   M3. I tried to run a mailing list using multidrop, and I have a mail
   loop!
   M4. My multidrop fetchmail seems to be having DNS problems.
   M5. I'm seeing long DNS delays before each message is processed.
   M6. How do I get multidrop mode to work with majordomo?
   
                                 Mangled mail:
                                       
   X1. Spurious blank lines are appearing in the headers of fetched mail.
   X2. My mail client can't see a Subject line.
   X3. Messages containing "From" at start of line are being split.
   X4. My mail is being mangled in a new and different way.
   
                                Other Problems:
                                       
   O1. The --logfile option doesn't work if the logfile doesn't exist.
   O2. Every time I get a POP or IMAP message the header is dumped to all
   my terminal sessions.
   O3. Does fetchmail reread its rc file every poll cycle?
   O4. Why do deleted messages show up again when I take a line hit while
   downloading?
   O5. Why is fetched mail being logged with my name, not the real From
   address?
   O6. I'm seeing long sendmail delays at start of each poll cycle.
   O7. Why doesn't fetchmail deliver mail in date-sorted order?
   
                                   Answers:
     _________________________________________________________________
   
G1. What is fetchmail and why should I bother?

   Fetchmail is a one-stop solution to the remote mail retrieval problem
   for Unix machines, quite useful to anyone with an intermittent PPP or
   SLIP connection to a remote mailserver. It can collect mail using any
   variant of POP or IMAP and forwards via port 25 to the local SMTP
   listener, enabling all the normal forwarding/filtering/aliasing
   mechanisms that would apply to local mail or mail arriving via a
   full-time TCP/IP connection.
   
   Fetchmail is not a toy or a coder's learning exercise, but an
   industrial-strength tool capable of transparently handling every
   retrieval demand from those of a simple single-user ISP connection up
   to mail retrieval and rerouting for an entire client domain. Fetchmail
   is easy to configure, unobtrusive in operation, powerful,
   feature-rich, and well documented. Extensive testing by a large,
   multi-platform user community has shown that fetchmail is as near
   bulletproof as the underlying protocols permit.
   
   If you found this FAQ in the distribution, see the README for
   fetchmail's full feature list.
     _________________________________________________________________
   
G2. Where do I find the latest FAQ and fetchmail sources?

   The latest HTML FAQ is available alongside the latest fetchmail
   sources at the fetchmail home page:
   http://www.ccil.org/~esr/fetchmail. You can also find both in the POP
   mail tools directory on Sunsite.
   
   A text dump of this FAQ is included in the fetchmail distribution.
   Because it freezes at distribution release time, it may not be
   completely current.
     _________________________________________________________________
   
G3. I think I've found a bug. Will you fix it?

   Yes I will, provided you include enough diagnostic information for me
   to go on. Send bugs to fetchmail-friends. When reporting bugs, please
   include the following:
    1. Your operating system and compiler version.
    2. Any command-line options you used.
    3. The output of fetchmail -V called with whatever other command-line
       options you used.
       
   It is helpful if you include your .fetchmailrc, but not necessary
   unless your symptom seems to involve an error in configuration
   parsing.
   
   If fetchmail seems to run and fetch mail, but the headers look mangled
   (that is headers are missing, or blank lines are inserted in the
   headers) then read the FAQ items in section X before submitting a bug
   report. Pay special attention to the item on diagnosing mail mangling.
   There are lots of ways for other programs in the mail chain to screw
   up that look like fetchmail's fault, but you may be able to fix these
   by tweaking your configuration.
   
   A transcript of the failed session with -v on is almost always useful.
   It is very important that the transcript include your POP/IMAP
   server's greeting line, so I can identify it in case of server
   problems.
   
   If the bug involves a core dump or hang, a gdb stack trace is good to
   have. (Bear in mind that you can attach gdb to a running but hung
   process by giving the process ID as a second argument.) You will need
   to reconfigure with
   

CFLAGS=-g LDFLAGS=" " ./configure

   and then rebuild in order to generate a version that can be
   gdb-traced.
   
   Best of all is a mail file which, when fetched, will reproduce the bug
   under the latest (current) version.
   
   Any bug I can reproduce will usually get fixed very quickly, often
   within 48 hours. Bugs I can't reproduce are a crapshoot. If the
   solution isn't obvious when I first look, it may evade me for a long
   time (or to put it another way, fetchmail is well enough tested that
   the easy bugs have long since been found). So if you want your bug
   fixed rapidly, it is not just sufficient but nearly necessary that you
   give me a way to reproduce it.
     _________________________________________________________________
   
G4. I have this idea for a neat feature. Will you add it?

   Probably not. Most of the feature suggestions I get are for ways to
   set various kinds of administrative policy or add more spam filtering
   (the most common one, which I used to get about four million times a
   week and got really tired of, is for tin-like kill files).
   
   You can do spam filtering better with procmail or mailagent on the
   server side and (if you're the server sysadmin) sendmail.cf domain
   exclusions. You can do other policy things better with the mda option
   and script wrappers around fetchmail. If it's a
   prime-time-vs.-non-prime-time issue, ask yourself whether a wrapper
   script called from crontab would do the job.
   
   I'm not going to do these; fetchmail's job is transport, not policy,
   and I refuse to change it from doing one thing well to attempting many
   things badly. One of my objectives is to keep fetchmail simple so it
   stays reliable.
   
   Furthermore, since about version 4.3.0 fetchmail has passed out of
   active development and been essentially stable. It is no longer my top
   project, and I am going to be quite reluctant to add features that
   might either jeopardize its stability or or involve me in large
   amounts of coding.
   
   All that said, if you have a feature idea that really is about a
   transport problem that can't be handled anywhere but fetchmail, lay it
   on me. I'm very accommodating about good ideas.
     _________________________________________________________________
   
G5. Is there a mailing list for exchanging tips?

   There is a fetchmail-friends list for people who want to discuss fixes
   and improvements in fetchmail and help co-develop it. It's at
   fetchmail-friends@thyrsus.com. There is also an announcements-only
   list, fetchmail-announce@thyrsus.com.
   
   Both lists are SmartList reflectors; sign up in the usual way with a
   message containing the word "subscribe" in the subject line sent to
   fetchmail-friends-request@thyrsus.com or
   fetchmail-announce-request@thyrsus.com. (Similarly, "unsubscribe" in
   the Subject line unsubscribes you, and "help" returns general list
   help)
     _________________________________________________________________
   
G6. So, what's this I hear about a fetchmail paper?

   Now it can be told! The fetchmail development was also a sociological
   experiment, an extended test to see if my theory about the critical
   features of the Linux development model is correct.
   
   The experiment was a success. I wrote a paper about it titled The
   Cathedral and the Bazaar which was first presented at Linux Kongress
   '97 in Bavaria and very well received there. It was also given at
   Atlanta Linux Expo, Linux Pro '97 in Warsaw, and the first Perl
   Conference, and will be an invited presentation at Usenix and UniForum
   '98. The folks at Netscape tell me it helped them decide to give away
   the source for Netscape Communicator).
   
   If you're reading a non-HTML dump of this FAQ, you can find the paper
   on the Web with a search for that title.
     _________________________________________________________________
   
G7. What is the best server to use with fetchmail?

   Fetchmail will work with any POP, IMAP, or ESMTP/ETRN server that
   conforms to the relevant RFCs (and even some oughtright broken ones
   like Microsoft Exchange). This doesn't mean it works equally well with
   all, however. POP2 servers, and POP3 servers without LAST, limit
   fetchmail's capabilities in various ways described on the manual page.
   
   Most modern Unixes (and effectively all Linux/*BSD systems) come with
   POP3 support preconfigured (but beware of the horribly broken POP3
   server mentioned in D2). An increasing minority also feature IMAP (you
   can detect IMAP support by running fetchmail in AUTO mode).
   
   If you have the option, we recommend using or installing IMAP4; it has
   the best facilities for tracking message "seen" states. It also
   recovers from interrupted connections more gracefully than POP3, and
   enables some significant performance optimizations.
   
   You can find sources for IMAP software at The IMAP Connection; we like
   the freeware UW IMAP and Cyrus products. UW IMAP is the reference
   implementation of IMAP.
     _________________________________________________________________
   
G8. How can I avoid sending my password en clair?

   Depending on what your mail server you are talking to, this ranges
   from trivial to impossible. It may even be next to useless.
   
   Most people use fetchmail over phone wires, which are hard to tap.
   Anybody with the skill and resources to do this could get into your
   server mailbox with much less effort by subverting the server host. So
   if your provider setup is modem wires going straight into a service
   box, you probably don't need to worry.
   
   In general there is little point in trying to secure your fetchmail
   transaction unless you trust the security of the server host you are
   retrieving mail from. Your vulnerability is more likely to be an
   insecure local network on the server end (e.g. to somebody with a
   TCP/IP packet sniffer intercepting Ethernet traffic between the modem
   concentrator you dial in to and the mailserver host).
   
   Having realized this, you need to ask whether password encryption
   alone will really address your security exposure. If you think you
   might be snooped, it's better to use end-to-end encryption on your
   whole mail stream so none of it can be read. One of the advantages of
   fetchmail over conventional SMTP-push delivery is that you may be able
   to arrange this by using ssh(1); see C4.
   
   If ssh/sshd isn't available, or you find it too complicated for you to
   set up, password encryption will at least keep a malicious cracker
   from deleting your mail, and require him to either tap your connection
   continuously or crack root on the server in order to read it.
   
   You can deduce what encryptions your mail server has available by by
   looking at the server greeting line (and, for IMAP, the response to a
   CAPABILITY query). Do a fetchmail -v to see these, or telnet direct to
   the server port (110 for POP3, 143 for IMAP).
   
   The facility you are most likely to have available is APOP. This is a
   POP3 feature supported by many servers. If you see something in the
   greeting line that looks like an angle-bracket-enclosed Internet
   address with a numeric left-hand part, that's an APOP challenge (it
   will vary each time you log in). You can register a secret on the host
   (using popauth(8) or some program like it). Specify the secret as your
   password in your .fetchmailrc; it will be used to encrypt the current
   challenge, and the encrypted form will be sent back the the server for
   verification.
   
   Alternatively, you may have Kerberos available. This may require you
   to set up some magic files in your home directory on your client
   machine, but means you can omit specifying any password at all.
   
   Fetchmail supports two different Kerberos schemes. One is a POP3
   variant called KPOP; consult the documentation of your mail server to
   see if you have it (one clue is the string "krb-IV" in the greeting
   line on port 110). The other is an IMAP facility described by RFC1731.
   You can tell if this one is present by looking for AUTH=KERBEROS_V4 in
   the CAPABILITY response.
   
   If you are fetching mail from a CompuServe POP3 account, you can use
   their RPA authentication (which works much like APOP). See T7 for
   details.
   
   Your POP3 server may have the RFC1938 OTP capability to use one-time
   passwords (if it doesn't, you can get OTP patches for the 2.2 version
   of the Qualcomm popper from Craig Metz). To check this, look for the
   string "otp-" in the greeting line. If you see it, and your fetchmail
   was built with OPIE support compiled in (see the distribution INSTALL
   file), fetchmail will detect it also. When using OTP, you will specify
   a password but it will not be sent en clair.
   
   Sadly, there is at present (February 1998) no OTP or APOP-like
   facility generally available on IMAP servers. However, there do exist
   patches which will OTP-enable the University of Washington IMAP
   daemon, version 4.1-BETA.
   
   You can get both POP3 and IMAP OTP patches from Craig Metz, over FTP
   via either ftp://ftp.inner.net/pub/opie/patches (IPv4) or
   ftp://ftp.ipv6.inner.net/pub/opie/patches (IPv6).MP> These patches use
   a SASL authentication method named "X-OTP" because there is not
   currently a standard way to do this; fetchmail also uses this method,
   so the two will interoperate happily. They better, because this is how
   Craig gets his mail ;)
   
   (One important win of OTP is that it's not subject to ITAR
   restrictions.)
     _________________________________________________________________
   
G9. Is any special configuration needed to use a dynamic IP address?

   Yes. In order to avoid giving indigestion to certain picky MTAs
   (notably exim), fetchmail always makes the RCPT TO address it feeds
   the MTA a fully qualified one with a hostname part. Normally it does
   this by appending @ and your client machine's hostname.
   
   This, however, can create problems when fetchmail is running in daemon
   mode and outlasts the dynamic IP address assignment your client
   machine had when it started up.
   
   Since the new IP address (looked up at RCPT TO interpretation time)
   doesn't match the original, the most benign possible result is that
   your MTA thinks it's seeing a relaying attempt and refuses. More
   frequently, fetchmail will try to connect top a nonexistent host
   address and time out. Worst case, you could up forwarding your mail to
   the wrong machine!
   
   Use the smtpaddress option to force the appended hostname to one with
   a (fixed) IP address of 127.0.0.1 in your /etc/hosts. (The name
   `localhost' will usually work; or you can use the IP address itself).
   
   Only one fetchmail option interacts directly with your IP address,
   `interface'. This option can be used to set the gateway device and
   restrict the IP address range fetchmail will use. Such a restriction
   is sometimes useful for security reasons, especially on multihomed
   sites. See C3.
   
   I recommend against trying to set up the interface option when
   initially developing your poll configuration -- it's never necessary
   to do this just to get a link working. Get the link working first,
   observe the actual address range you see on connections, and add an
   interface option (if you need one) later.
     _________________________________________________________________
   
G10. Is any special configuration needed to use firewalls?

   No. You can use fetchmail with SOCKS, the standard tool for
   indirecting TCP/IP through a firewall. You can find out about SOCKS,
   and download the SOCKS software including server and client code, at
   the SOCKS distribution site.)
   
   The specific recipe for using fetchmail with a firewall is at T10
     _________________________________________________________________
   
B1. Lex bombs out while building the fetchmail lexer.

   In the immortal words of Alan Cox the last time this came up: "Take
   the Solaris lex and stick it up the backside of a passing Sun
   salesman, then install flex and use that. All will be happier."
   
   I couldn't have put it better myself, and aren't going to try now.
     _________________________________________________________________
   
B2. I get link failures when I try to build fetchmail.

   If you get errors resembling these
   
mxget.o(.text+0x35): undefined referenceto `__res_search'
mxget.o(.text+0x99): undefined reference to`__dn_skipname'
mxget.o(.text+0x11c): undefined reference to`__dn_expand'
mxget.o(.text+0x187): undefined reference to`__dn_expand'
make: *** [fetchmail] Error 1

   then you must add "-lresolv" to the LOADLIBS line in your Makefile
   once you have installed the `bind' package.
     _________________________________________________________________
   
F1. Why does my old .fetchmailrc file no longer work?

  If your file predates 4.0.6:
  
   Just after the `via' option was introduced, I realized that the
   interactions between the `via', `aka', and `localdomains' options were
   out of control. Their behavior had become complex and confusing, so
   much so that I was no longer sure I understood it myself. Users were
   being unpleasantly surprised.
   
   Rather than add more options or crock the code, I re-thought it. The
   redesign simplified the code and made the options more orthogonal, but
   may have broken some complex multidrop configurations. Any multidrop
   configurations that depended on the name just after the `poll' or
   `skip' keyword being still interpreted as a DNS name for
   address-matching purposes, even in the presence of a `via' option,
   will break.
   
   It is theoretically possible that other unusual configurations (such
   as those using a non-FQDN poll name to generate Kerberos IV tickets)
   might also break; the old behavior was sufficiently murky that we
   can't be sure. If you think this has happened to you, contact the
   maintainer.
   
  If your file predates 3.9.5:
  
   The `remote' keyword has been changed to `folder'. If you try to use
   the old keyword, the parser will utter a warning.
   
  If your file predates 3.9:
  
   It could be because you're using a .fetchmailrc that's written in the
   old popclient syntax without an explicit `username' keyword leading
   the first user entry attached to a server entry. This error can be
   triggered by having a user option such as `keep' or `fetchall' before
   the first explicit username. For example, if you write
   
poll openmail protocol pop3
        keep user "Hal DeVore" there is hdevore here

   the `keep' option will generate an entire user entry with the default
   username (the name of fetchmail's invoking user).
   
   The popclient compatibility syntax was removed in 4.0. It complicated
   the configuration file grammar and confused users.
   
  If your file predates 2.8:
  
   The `interface', `monitor' and `batchlimit' options changed after 2.8.
   
   They used to be global options with `set' syntax like the batchlimit
   and logfile options. Now they're per-server options, like `protocol'.
   
   If you had something like
   
        set interface = "sl0/10.0.2.15"

   in your .fetchmailrc file, simply delete that line and insert
   `interface sl0/10.0.2.15' in the server options part of your
   `defaults' declaration.
   
   Do similarly for any `monitor' or `batchlimit' options.
     _________________________________________________________________
   
F2. The .fetchmailrc parser won't accept my all-numeric user name.

   So put string quotes around it. :-)
   
   The configuration file parser treats any all-numeric token as a
   number, which will confuse it when it's expecting a name. String
   quoting forces the token's class.
     _________________________________________________________________
   
F3. The .fetchmailrc parser won't accept my host or username beginning with
`no'.

   You're caught in an unfortunate crack between the newer-style syntax
   for negated options (`no keep', `no rewrite' etc.) and the older style
   run-on syntax (`nokeep', `norewrite' etc.).
   
   You can work around this easily. Just put string quotes around your
   token.
   
   I haven't fixed this because there is no good fix for it short of
   implementing a token pushback stack in the lexer. That's more
   additional complexity than I'm willing to add to banish a very
   marginal bug with an easy workaround.
     _________________________________________________________________
   
F4. I'm migrating from popclient. How do I need to modify my .poprc?

   If you have been using popclient (the ancestor of this program) at
   version 3.0b6 or later, start with this
   
(cd; mv .poprc .fetchmailrc)

   and do fetchmail -V to see if fetchmail's parser understands your
   configuration.
   
   Be aware that some of popclient's unnecessary options have been
   removed (see the NOTES file in the distribution for explanation). You
   can't deliver to a local mail file or to standard output any more, and
   using an MDA for delivery is discouraged. If you throw those options
   away, fetchmail will now forward your mail into your system's normal
   Internet-mail delivery path.
   
   Actually, using an MDA is now almost always the wrong thing; the MDA
   facility has been retained only for people who can't or won't run a
   sendmail-like SMTP listener on port 25. The default, SMTP forwarding
   to port 25, is better for at least three major reasons. One: it feeds
   retrieved POP and IMAP mail into your system's normal delivery path
   along with local mail and normal Internet mail, so all your normal
   filtering/aliasing/forwarding setup for local mail works. Two: because
   the port 25 listener returns a positive acknowledge, fetchmail can be
   sure you're not going to lose mail to a disk-full or some other
   resource-exhaustion problem. Three: it means fetchmail doesn't have to
   know where the system mailboxes are, or futz with file locking (which
   makes two fewer places for it to potentially mess up).
   
   If you used to use -mda "procmail -d <you>" or something similar,
   forward to port 25 and do "| procmail -d <you>" in your ~/.forward
   file.
   
   As long as your new .fetchmailrc file does not use the removed
   `localfolder' option or `limit' (which now takes a maximum byte size
   rather than a line count), a straight move or copy of your .poprc will
   often work. (The new run control file syntax also has to be a little
   stricter about the order of options than the old, in order to support
   multiple user descriptions per server; thus you may have to rearrange
   things a bit.)
   
   Run control files in the minimal .poprc format (without the `username'
   token) will trigger a warning. To eliminate this warning, add the
   `username' keyword before your first user entry per server (it is
   already required before second and subsequent user entries per server.
   
   In some future version the `username' keyword will be required.
     _________________________________________________________________
   
F5. I'm getting a `parse error' message I don't understand.

   The most common cause of mysterious parse errors is putting a server
   option after a user option. Check the manual page; you'll probably
   find that by moving one or more options closer to the `poll' keyword
   you can eliminate the problem.
   
   Yes, I know these ordering restrictions are hard to understand.
   Unfortunately, they're necessary in order to allow the `defaults'
   feature to work.
     _________________________________________________________________
   
C1. Why do I need a .fetchmailrc when running as root on my own machine?

   Ian T. Zimmerman <itz@rahul.net> asked:
   
   On the machine where I'm the only real user, I run fetchmail as root
   from a cron job, like this:
   
    fetchmail -u "itz" -p POP3 -s bolero.rahul.net

   This used to work as is (with no .fetchmailrc file in root's home
   directory) with the last version I had (1.7 or 1.8, I don't remember).
   But with 2.0, it RECPs all mail to the local root user, unless I
   create a .fetchmailrc in root's home directory containing:
   
     skip bolero.rahul.net proto POP3
          user itz is itz

   It won't work if the second line is just "user itz". This is silly.
   
   It seems fetchmail decides to RECP the `default local user' (ie. the
   uid running fetchmail) unless there are local aliases, and the
   `default' aliases (itz->itz) don't count. They should.
   
   Answer:
   
   No they shouldn't. I thought about this for a while, and I don't much
   like the conclusion I reached, but it's unavoidable. The problem is
   that fetchmail has no way to know, in general, that a local user `itz'
   actually exists.
   
   "Ah!" you say, "Why doesn't it check the password file to see if the
   remote name matches a local one?" Well, there are two reasons.
   
   One: it's not always possible. Suppose you have an SMTP host declared
   that's not the machine fetchmail is running on? You lose.
   
   Two: How do you know server itz and SMTP-host itz are the same person?
   They might not be, and fetchmail shouldn't assume they are unless
   local-itz can explicitly produce credentials to prove it (that is, the
   server-itz password in local-itz's .fetchmailrc file.).
   
   Once you start running down possible failure modes and thinking about
   ways to tinker with the mapping rules, you'll quickly find that all
   the alternatives to the present default are worse or unacceptably more
   complicated or both.
     _________________________________________________________________
   
C2. How can I arrange for a fetchmail daemon to get killed when I log out?

   Fetchmail versions before 2.3 actually used SIGHUP as a wakeup signal.
   Newer versions use SIGUSR1 for wakeup (and SIGHUP only in
   background-daemon mode) in order to avoid any potential confusion
   about logout-time behavior. The right way to dispatch fetchmail on
   logout is to arrange for the command `fetchmail -q' to be called on
   logout.
   
   Under bash, you can arrange this by putting `fetchmail -q' in the file
   `~/.bash_logout'. Most csh variants execute `~/.logout' on logout. For
   other shells, consult your shell manual page.
     _________________________________________________________________
   
C3. How do I know what interface and address to use with --interface?

   This depends a lot on your local networking configuration (and right
   now you can't use it at all except under Linux). However, here are
   some important rules of thumb that can help. If they don't work, ask
   your local sysop or your Internet provider.
   
   First, you may not need to use --interface at all. If your machine
   only ever does SLIP or PPP to one provider, it's almost certainly by a
   point to point modem connection to your provider's local subnet that's
   pretty secure against snooping (unless someone can tap your phone or
   the provider's local subnet!). Under these circumstances, specifying
   an interface address is fairly pointless.
   
   What the option is really for is sites that use more than one
   provider. Under these circumstances, typically one of your provider IP
   addresses is your mailserver (reachable fairly securely via the modem
   and provider's subnet) but the others might ship your packets
   (including your password) over unknown portions of the general
   Internet that could be vulnerable to snooping. What you'll use
   --interface for is to make sure your password only goes over the one
   secure link.
   
   To determine the device:
   
    1. If you're using a SLIP link, the correct device is probably sl0.
    2. If you're using a PPP link, the correct device is probably ppp0.
    3. If you're using a direct connection over a local network such as
       an ethernet, use the command `netstat -r' to look at your routing
       table. Try to match your mailserver name to a destination entry;
       if you don't see it in the first column, use the `default' entry.
       The device name will be in the rightmost column.
       
   To determine the address and netmask:
   
    1. If you're talking to slirp, the correct address is probably
       10.0.2.15, with no netmask specified. (It's possible to configure
       slirp to present other addresses, but that's the default.)
    2. If you have a static IP address, run `ifconfig <device>', where
       <device> is whichever one you've determined. Use the IP address
       given after "inet addr:". That is the IP address for your end of
       the link, and is what you need. You won't need to specify a
       netmask.
    3. If you have a dynamic IP address, your connection IP will vary
       randomly over some given range (that is, some number of the least
       significant bits change from connection to connection). You need
       to declare an address with the variable bits zero and a
       complementary netmask that sets the range.
       
   To illustrate the rule for dynamic IP addresses, let's suppose you're
   hooked up via SLIP and your IP provider tells you that the dynamic
   address pool is 255 addresses ranging from 205.164.136.1 to
   205.164.136.255. Then
   
        interface "sl0/205.164.136.0/255.255.255.0"

   would work. To range over any value of the last two octets (65536
   addresses) you would use
   
        interface "sl0/205.164.0.0/255.255.0.0"
     _________________________________________________________________
   
C4. How can I get fetchmail to work with ssh?

   We have two recipes for this. The first is a little easier to set up,
   but only supports one user at a time.
   
   First, a lightly edited version of a recipe from Masafumi NAKANE:
   
   1. You must have ssh (the ssh client) on the local host and sshd (ssh
   server) on the remote mail server. And you have to configure ssh so
   you can login to the sshd server host without a password. (Refer to
   ssh man page for several authentication methods.)
   
   2. Add something like following to your .fetchmailrc file:
   
poll mailhost port 1234 via localhost with proto pop3:
        preconnect "ssh -f -L 1234:mailhost:110 mailhost sleep 20 </dev/null >/
dev/null";

   (Note that 1234 can be an arbitrary port number. Privileged ports can
   be specified only by root.) The effect of this ssh command is to
   forward connections made to localhost port 1234 (in above example) to
   mailhost's 110.
   
   This configuration will enable secure mail transfer. All the
   conversation between fetchmail and remote pop server will be
   encrypted.
   
   If sshd is not running on the remote mail server, you can specify
   intermediate host running it. If you do this, however, communication
   between the machine running sshd and the POP server will not be
   encrypted. And the preconnect line would be like this:
   
preconnect "ssh -f -L 1234:mailhost:110 sshdhost sleep 20 </dev/null >/dev/null
"

   You can work this trick with IMAP too, but the port number 110 in the
   above would need to become 143.
   
   Second, a recipe from Charlie Brady <cbrady@ind.tansu.com.au>:
   
   Charlie says: "The [previous] recipe certainly works, but the solution
   I post here is better in a few respects":
     * this method will not fail if two or more users attempt to use
       fetchmail simultaneously.
     * you are able to use the full facilities of tcpd to control access
     * this method does not depend on the preconnect feature of
       fetchmail, so can be used for tunneling of other services as well.
       
   Here are the steps:
    1. Make sure that the "socket" program is installed on the server
       machine.
    2. Set up an unprivileged account on your system with a .ssh
       directory containing an SSH identity file "identity" with no pass
       phrase, "identity.pub" and "known_hosts" containing the host key
       of your mailhost. Let's call this account "noddy".
    3. On mailhost, set up no-password access for noddy@yourhost. Add to
       your SSH authorised_keys file:

command="socket localhost 110",no-port-forwarding 1024 ......
   where "1024 ......" is the content of noddy's identity.pub file.
    4. Create a script /usr/local/bin/ssh.fm and make it executable:

#! /bin/sh
exec ssh -q -C -l your.login.id -e none mailhost socket localhost 110
    5. Add an entry in inetd.conf for whatever port you choose to use -
       say:

1234 stream tcp nowait noddy /usr/sbin/tcpd /usr/local/bin/ssh.fm
    6. Send a HUP signal to your inetd.
       
   Now just use localhost:1234 to access your POP server.
     _________________________________________________________________
   
C5. How can I set up support for sendmail's anti-spam 571 response?

   Rachel Polanskis writes:
   
   Basically you need to use the "check_*" rules in sendmail. These are
   rules introduced since version 8.8.2
   
   The idea is to generate a list of domains and addresses that are
   placed into a file - I call mine "sendmail.rej" and you place just one
   domain or email address on each line. During the SMTP transaction,
   this file is checked and if there is a match, the message is refused,
   with a suitable "Service not available" message sent back to the
   sender.
   
   With the feature enabled in fetchmail, the mail is simply deleted,
   with no further processing.
   
   The only drawback when blocking spam with fetchmail is that you do not
   get the satisfaction of sending an error back to the sender.
   
   To actually use the check_mail rules in sendmail 8.8.2 or better, you
   need to know how to generate a sendmail.cf file from the m4 config
   files distributed with sendmail.
   
   The actual rules can be found at the following URLS:
   
   http://www.informatik.uni-kiel.de/%7Eca/email/check.html
   
   This one is by Claus Aßman, who has documented more of sendmail then I
   can digest! Remember, when copying these rulesets off the web, that
   there are tabs embedded in them, that may not be preserved. You must
   reintroduce these tabs into the rules to make them work properly.
   
   Once you have your ruleset in place, and have generated a nice
   sendmail.cf file, and the list of blocked sites, try telneting to your
   SMTP port to test it, and send a message with a blocked address in it.
   
   You should see a message similar to:
   
     "571 unsolicited email is refused"

   Next, if you have access to a host that you can send mail from, that
   is not your mail host, add that host to your spamlist and restart
   sendmail.
   
   Send a message to your mailing address from that host and then pop off
   the message with fetchmail, using the -v argument. You can monitor the
   SMTP transaction, and when the FROM address is parsed, if sendmail
   sees that it is an address in spamlist, fetchmail will flush and
   delete it.
   
   Under no circumstances put your mailhost or any host you accept mail
   from using fetchmail into your reject file. You will lose mail if you
   do this!!!
   
   The check_ rules work, and they work well. Coupled with fetchmail's
   ability to respond to the appropriate error messages, you can be
   assured of never seeing a spam from any address you put in the reject
   list.
   
   The only thing that is missing, as mentioned previously, is the
   ability to allow sendmail to process the message further and generate
   an error message to the sender.
     _________________________________________________________________
   
C6. How can I do automatic startup/shutdown of fetchmail when I may have
multiple login sessions going?

   In the contrib subdirectory of the fetchmail distribution there is
   some shell code you can add to your .bash_login and .bash_logout
   profiles that will accomplish this. Thank James Laferriere
   <babydr@nwrain.net> for it.
     _________________________________________________________________
   
T1. How can I use fetchmail with sendmail?

   For most sendmails, no special configuration is required. Eric Allman
   tells me that if FEATURE(always_add_domain) is included in sendmail's
   configuration, you can leave the rewrite option off.
   
   Günther Leber reports that Digital Unix sendmails won't work with
   fetchmail. The symptom is an error message "553 Local configuration
   error, hostname not recognized as local". The problem is that
   fetchmail normally feeds sendmail with the client machine's host
   address in the MAIL FROM line. These sendmails think this means
   they're seeing the result of a mail loop and suppress the mail. You
   may be able to work around this by running in --invisible mode.
     _________________________________________________________________
   
T2. How can I use fetchmail with qmail?

   Turn on the forcecr option; qmail's listener mode doesn't like header
   or message lines terminated with bare linefeeds.
   
   (This information is thanks to Robert de Bath
   <robert@mayday.cix.co.uk>.)
   
   If a mailhost is using the qmail package (see
   http://pobox.com/~djb/qmail.html) then, providing the local hosts are
   also using qmail, it is possible to set up one fetchmail link to be
   reliably collect the mail for an entire domain.
   
   One of the basic features of qmail is the `Delivered-To:' message
   header. Whenever qmail delivers a message to a local mailbox it puts
   the username and hostname of the envelope recipient on this line. The
   major reason for this is to prevent mail loops.
   
   To set up qmail to batch mail for a disconnected site the ISP-mailhost
   will have normally put that site in its `virtualhosts' control file so
   it will add a prefix to all mail addresses for this site. This results
   in mail sent to 'username@userhost.userdom.dom.com' having a
   'Delivered-To:' line of the form:
   
       Delivered-To: mbox-userstr-username@userhost.userdom.dom.com

   A single host maildrop will be slightly simpler:
       Delivered-To: mbox-userstr-username@userhost.dom.com

   The ISP can make the 'mbox-userstr-' prefix anything they choose but a
   string matching the user host name is likely.
   
   To use this line you must:
   
    1. Ensure the option `envelope Delivered-To:' is in the fetchmail
       config file.
    2. Ensure you have a localdomains containing 'userdom.dom.com' or
       `userhost.dom.com' respectively.
       
   So far this reliably delivers messages to the correct machine of the
   local network, to deliver to the correct user the 'mbox-userstr-'
   prefix must be stripped off of the user name. This can be done by
   setting up an alias within the qmail MTA on each local machine. Simply
   create a dot-qmail file called '.qmail-mbox-userstr-default' in the
   alias directory (normally /var/qmail/alias) with the contents:
   
      | ../bin/qmail-inject -a -f"$SENDER" "${LOCAL#mbox-userstr-}@$HOST}"

   Note this does require a modern /bin/sh.
   
   Luca Olivetti adds:
   
   If you aren't using qmail locally, or you don't want to set up the
   alias mechanism described above, you can use the option `qvirtual
   "mbox-userstr-"' in your fetchmail config file to strip the prefix
   from the local user name.
     _________________________________________________________________
   
T3. How can I use fetchmail with exim?

   By default, the exim listener enforces the the RFC1123 requirement
   that MAIL FROM and RCPT TO addresses you pass to it have to be
   canonical (e.g. with a fully qualified hostname part).
   
   Fetchmail always passes fully qualified RCPT TO addresses. But MAIL
   FROM is a potential problem if the MTAs upstream from your fetchmail
   don't necessarily pass canonicalized From and Return-Path addresses,
   and fetchmail's rewrite option is off. The specific case where this
   has come up involves bounce messages generated by sendmail on your
   mailer host, which have the (un-canonicalized) origin address
   MAILER-DAEMON.
   
   The right way to fix this is to enable the rewrite option and have
   fetchmail canonicalize From and Return-Path addresses with the
   mailserver hostname before exim sees them. This option is enabled by
   default, so it won't be off unless you turned it off.
   
   If you must run with rewrite off, there is a switch in exim's
   configuration files that allows it to accept domainless MAIL FROM
   addresses; you will have to flip it by putting the line
   
        sender_unqualified_hosts = localhost

   in the main section of the exim configuration file. Note that this
   will result in such messages having an incorrect domain name attached
   to their return address (your SMTP listener's hostname rather than
   that of the remote mail server).
     _________________________________________________________________
   
T4. How can I use fetchmail with smail?

   Smail 3.2 is very nearly plug-compatible with sendmail, and may work
   fine out of the box.
   
   We have one report that when processing multiple messages from a
   single fetchmail session, smail sometimes delivers them in an order
   other than received-date order. This can be annoying because it
   scrambles conversational threads. This is not fetchmail's problem, it
   is an smail "feature" and has been reported to the maintainers as a
   bug.
   
   Very recent smail versions require an -smtp_hello_verify option in the
   smail config file. This overrides smail's check to see that the HELO
   address is actually that of the client machine, which is never going
   to be the case when fetchmail is in the picture. According to RFC1123
   an SMTP listener must allow this mismatch, so smail's new behavior
   (introduced sometime between 3.2.0.90 and 3.2.0.95) is a bug.
     _________________________________________________________________
   
T5. How can I use fetchmail with SCO's MMDF?

   We're told this is possible, but difficult and tricky (and we don't
   have the recipe for it). Our informant suggests dropping MMDF and
   using sendmail instead.
     _________________________________________________________________
   
T6. How can I use fetchmail with Lotus Notes?

   The Lotus Notes SMTP gateway tries to deduce when it should convert \n
   to \r\n, but its rules are not intuitive. Use `forcecr'.
     _________________________________________________________________
   
T7. How can I use fetchmail with Microsoft Exchange?

   M$ Exchange violates the POP3 RFCs. Its LIST command does not reveal
   the real sizes of mail in the pop mailbox, but the sizes of the
   compressed versions in the exchange mail database (thanks to Arjan De
   Vet and Guido Van Rooij for alerting us to this problem).
   
   Fetchmail works with M$ Exchange, despite this braindamage. Two
   features are compromised. One is that the --limit option will not work
   right (it will check against compressed and not actual sizes). The
   other is that a too-small SIZE argument may be passed to your ESMTP
   listener, assuming you're using one (this should not be a problem
   unless the actual size of the message is above the listener's
   configured length limit).
   
   If you want these fixed, go bug the Evil Empire. Or, better yet,
   install a real operating system on your server and run IMAP.
     _________________________________________________________________
   
T8. How can I use fetchmail with CompuServe RPA?

   First, make sure your fetchmail has the RPA support compiled in. Stock
   fetchmail binaries (such as you might get from an RPM) don't. You can
   check this by looking at the output of fetchmail -V; if you see the
   string "+RPA" after the version ID you're good to go, otherwise you'll
   have to build your own from sources (see the INSTALL file in the
   source distribution for directions).
   
   Give your RPA pass-phrase as your password. An RPA-enabled fetchmail
   will automatically check for csi.com in the POP server's greeting
   line. If that's found, it will query the server to see if it is
   RPA-capable, and if so do an RPA transaction rather than a plain-text
   password handshake.
     _________________________________________________________________
   
T9. How can I use fetchmail with HP OpenMail?

   No special configuration is required, but OpenMail has an annoying bug
   similar to the big one in Microsoft Exchange. The message sizes it
   gives in the LIST are rounded to the nearest 1024 bytes. It also has a
   nasty habit of discarding headers it doesn't recognize, such as X- and
   Resent- headers.
   
   As with M$ Exchange, the only real fix for these problems is to get a
   POP server that isn't brain-dead.
     _________________________________________________________________
   
T10. How can I use fetchmail with SOCKS?

   Daniel Sobral <dcs@gns.com.br gave us the following recipe:
   
    1. Install socks5. You don't need to have a socks server, you just
       want the "runsocks" program.
    2. Set the environment variable SOCKS_SERVER to the server you'll be
       using. Alternatively, you may set SOCKS4_SERVER and/or
       SOCKS5_SERVER. Eg:

        export SOCKS5_SERVER=socks.my.domain.com
    3. Set SOCKS5_USER and SOCKS5_PASSWD if needed.
    4. Run fetchmail through runsocks. Just like this:

        runsocks fetchmail [parameters to fetchmail]

   It wasn't that hard, was it? :-)
     _________________________________________________________________
   
T11. How can I use fetchmail with IPv6 and IPsec?

   To use fetchmail with IPv6, you need a system that supports IPv6, the
   "Basic Socket Interface Extensions for IPv6" (RFC 2133), and the
   inet6-apps kit. This currently means that you need to have a BSD/OS or
   NetBSD system with the NRL IPv6+IPsec software distribution or a Linux
   system with the latest experimental kernel and net-tools. It should
   not be hard to build fetchmail on other IPv6 implementations if you
   can port the inet6-apps kit.
   
   To use fetchmail with network security (read: IPsec), you need a
   system that supports IPsec, the API described in the "Network Security
   API for Sockets" (draft-metz-net-security-api-01.txt), and the
   inet6-apps kit. This currently means that you need to have a BSD/OS or
   NetBSD system with the NRL IPv6+IPsec software distribution. A Linux
   IPsec implementation supporting this API will probably appear in the
   coming months.
   
   The NRL IPv6+IPsec software distribution can be obtained from:
   http://web.mit.edu/network/isakmp
   
   The inet6-apps kit can be obtained from
   ftp://ftp.ipv6.inner.net/pub/ipv6 (via IPv6) or
   ftp://ftp.inner.net/pub/ipv6 (via IPv4).
   
   More information on using IPv6 with Linux can be obtained from:
     * http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html
     * http://www.ipv6.inner.net/ipv6 (via IPv6)
     * http://www.inner.net/ipv6 (via IPv4)
     _________________________________________________________________
   
R1. Fetchmail's initial gethostbyname call fails on my host.

   This is probably due to a DNS or NIS misconfiguration. The first thing
   to do is check your /etc/hosts file for duplicate or missing entries
   related to your host.
     _________________________________________________________________
   
R2. Fetchmail isn't working, and -v shows `SMTP connect failed' messages.

   Fetchmail itself is probably working, but your SMTP port 25 listener
   is down or inaccessible.
   
   The first thing to check is if you can telnet to port 25 on your smtp
   host (which is normally `localhost' unless you've specified an smtp
   option in your .fetchmailrc or on the command line) and get a greeting
   line from the listener. If the SMTP host is inaccessible or the
   listener is down, fix that first.
   
   If the listener seems to be up when you test with telnet, the most
   benign and typical problem is that the listener had a momentary
   seizure due to resource exhaustion while fetchmail was polling it --
   process table full or some other problem that stopped the listener
   process from forking. If your SMTP host is not `localhost' or
   something else in /etc/hosts, the fetchmail glitch could also have
   been caused by transient nameserver failure.
   
   Try running fetchmail -v again; if it succeeds, you had one of these
   kinds of transient glitch. You can ignore these hiccups, because a
   future fetchmail run will get the mail through.
   
   If the listener tests up, but you have chronic failures trying to
   connect to it anyway, your problem is more serious. One way to work
   around chronic SMTP connect problems is to use --mda. But this only
   attacks the symptom; you may have a DNS or TCP routing problem. You
   should really try to figure out what's going on underneath before it
   bites you some other way.
   
   We have one report (from toby@eskimo.com) that you can sometimes solve
   such problems by doing an smtp declaration with an IP address that
   your routing table maps to something other than the loopback device
   (he used ppp0).
   
   We also have a report that this error can be caused by having an
   /etc/hosts file that associates your client host name with more than
   one IP address.
   
   It's also possible that your DNS configuration isn't looking at
   /etc/hosts at all. If you're using libc5, look at /etc/resolv.conf; it
   should say something like

        order hosts,bind

   so your /etc/hosts file is checked first. If you're running GNU libc6,
   check your /etc/nsswitch file. Make sure it says something like

        order hosts,bind

   again, in order to make sure /etc/hosts is seen first.
   
   We had another report from a Linux user of fetchmail 2.1 who solved
   his SMTP connection problem by removing the reference to -lresolv from
   his link line and relinking. Apparently in some older Linux
   distributions the libc bind library version works better.
   
   As of 2.2, the configure script has been hacked so the bind library is
   linked only if it is actually needed. So under Linux it won't be, and
   this particular cause should go away.
     _________________________________________________________________
   
R3. When I try to configure an MDA, fetchmail doesn't work.

   (I hear this one from people who have run into the blank-line problem
   in X1.)
   
   Try sending yourself test mail and retrieving it using the
   command-line options `-k -m cat'. This will dump exactly what
   fetchmail retrieves to standard output (plus the Received line
   fetchmail itself adds to the headers).
   
   If the dump doesn't match what shows up in your mailbox when you
   configure an MDA, your MDA is mangling the message. If it doesn't
   match what you sent, then fetchmail or something on the server is
   broken.
     _________________________________________________________________
   
R4. Fetchmail dumps core when given an invalid rc file.

   This is usually reported from AIX or Ultrix, but has even been known
   to happen on Linuxes without a recent version of flex installed. The
   problem appears to be a result of building with an archaic version of
   lex.
   
   Workaround: fix the syntax of your .fetchmailrc file.
   
   Fix: build and install the latest version of flex from the Free
   Software Foundation. An FSF mirror site will help you get it faster.
     _________________________________________________________________
   
R5. Fetchmail dumps core in -V mode, but operates normally otherwise.

   We've had this reported to us under Linux using libc-5.4.17 and
   gcc-2.7.2. It does not occur with libc-5.3.12 or earlier versions.
   
   Workaround: link with GNU malloc rather than the stock C library
   malloc.
   
   We're told there is some problem with the malloc() code in that
   version which makes it fragile in the presence of multiple free()
   calls on the same pointer (the malloc arena gets corrupted).
   Unfortunately it appears from doing gdb traces that whatever free()
   calls producing the problem are being made by the C library itself,
   not the fetchmail code (they're all from within fclose, and not an
   fclose called by fetchmail, either).
     _________________________________________________________________
   
R6. Fetchmail dumps core when I use a .netrc file but works otherwise.

   We have a report that under Solaris 2.5 using gcc-2.7.2, if fetchmail
   is compiled with -O or -O2, it segfaults on startup when reading a
   .netrc.
   
   You can work around this by disabling optimization.
   
   There may be an actual bug here that the optimizer exposes; the stack
   trace says the segfault is in free() and has all the earmarks of a
   heap- corruption screw. But the symptom doesn't reproduce under Linux
   with the same .fetchmailrc and .netrc.
     _________________________________________________________________
   
R7. Running fetchmail in daemon mode doesn't work.

   We have one report from a Solaris 4.1.4 user that trying to run
   fetchmail in detached daemon mode doesn't work, but that using the
   same options with -N (nodetach) is OK.
   
   If this happens, you have a specific portability problem with the code
   in daemon.c that detaches and backgrounds the daemon fetchmail. Tell
   me about it so I can try to fix it. As a workaround, you can start
   fetchmail with -N and an ampersand to background it.
   
   This should not happen under Linux or any truly POSIX-conformant Unix.
     _________________________________________________________________
   
R8. Fetchmail hangs when used with pppd.

   Your problem may be with pppd's `demand' option. We have a report that
   fetchmail doesn't play well with it, but works with pppd if `demand'
   is turned off. We have no idea why this is.
     _________________________________________________________________
   
D1. I think I've set up fetchmail correctly, but I'm not getting any mail.

   Maybe you have a .forward or alias set up that you've forgotten about.
   You should probably remove it.
   
   Or maybe you're trying to run fetchmail in multidrop mode as root
   without a .fetchmailrc file. This doesn't do what you think it should;
   see question C1.
   
   Or you may not be connecting to the SMTP listener. Run fetchmail -v
   and see R1.
     _________________________________________________________________
   
D2. All my mail seems to disappear after an interrupt.

   One POP3 daemon used in the Berkeley Unix world that reports itself as
   POP3 version 1.004 actually throws the queue away. 1.005 fixed that.
   If you're running this one, upgrade immediately.
   
   Many POP servers, if an interruption occurs, will restore the whole
   mail queue after about 10 minutes. Others will restore it right away.
   If you have an interruption and don't see it right away, cross your
   fingers and wait ten minutes before retrying.
   
   Some servers (such as Microsoft's NTMail) are mis-designed to restore
   the entire queue, including messages you have deleted. If you have one
   of these and it flakes out on you a lot, try setting a small
   --fetchlimit value. This will result in more IP connects to the server
   but will mean it actually executes changes to the queue more often.
   
   Qualcomm's qpopper, used at many BSD Unix sites, is better behaved. If
   its connection is dropped, it will first execute all DELE commands (as
   though you had issued a QUIT -- this is a technical violation of the
   POP3 RFCs, but a good idea in a world of flaky phone lines). Then it
   will re-queue any message that was being downloaded at hangup time.
   Still, qpopper may require a noticeable amount of time to do deletions
   and clean up its queue. (Fetchmail waits a bit before retrying in
   order to avoid a `lock busy' error.)
     _________________________________________________________________
   
D3. Mail that was being fetched when I interrupted my fetchmail seems to have
been vanished.

   Fetchmail only sends a delete mail request to the server when either
   (a) it gets a positive delivery acknowledgement from the SMTP
   listener, or (b) it gets an error 571 (the spam-filter error) from the
   listener. No interrupt can cause it to lose mail.
   
   However, POP3 has a design problem in that its servers mark a message
   `seen' as soon as the fetch command to get it is sent down. If for
   some reason the message isn't actually delivered (you take a line hit
   during the download, or your port 25 listener can't find enough free
   disk space, or you interrupt the delivery in mid-message) that `seen'
   message can lurk invisibly in your server mailbox forever.
   
   Workaround: add the `fetchall' keyword to your POP3 fetch options.
   
   Solution: switch to an IMAP server.
     _________________________________________________________________
   
M1. I've declared local names, but all my multidrop mail is going to root
anyway.

   Somehow your fetchmail is never matching the hostname part of
   recipient names to the name of the mailserver machine. This probably
   means it is unable to recognize hostname parts as being DNS names of
   the mailserver, and indicates some kind of DNS configuration problem
   either on the server or your client machine.
   
   The easiest workaround is to add a `via' option (if necessary) and add
   enough aka declarations to cover all of your mailserver's aliases,
   then say `no dns'. This will take DNS out of the picture (though it
   means mail may be uncollected if it's sent to an alias of the
   mailserver that you don't have listed).
   
   It would be better to fix your DNS, however. DNS problems can hurt you
   in lots of ways, for example by making your machines intermittently or
   permanently unreachable to the rest of the net.
     _________________________________________________________________
   
M2. I can't seem to get fetchmail to route to a local domain properly.

   A lot of people want to use fetchmail as a poor man's internetwork
   mail gateway, picking up mail accumulated for a whole domain in a
   single server mailbox and then routing based on what's in the
   To/Cc/Bcc lines.
   
   In general, this is not really a good idea. It would be smarter to
   just let the mail sit in the mailserver's queue and use fetchmail's
   ETRN mode to trigger SMTP sends periodically (of course, this means
   you have to poll more frequently than the mailserver's expiry period).
   If you can't arrange this, try setting up a UUCP feed.
   
   If neither of these alternatives is available, multidrop mode may do
   (though you are going to get hurt by some mailing list software; see
   the caveats under THE USE AND ABUSE OF MULTIDROP MAILBOXES on the man
   page). If you want to try it, the way to do it is with the
   `localdomains' option.
   
   In general, if you use localdomains you need to make sure of two other
   things:
   
   1. You've actually set up your .fetchmailrc entry to invoke multidrop
   mode.
   
   Many people set a `localdomains' list and then forget that fetchmail
   wants to see more than one name (or the wildcard `*') in a `here' list
   before it will do multidrop routing.
   
   2. You may have to set `no envelope'.
   
   Normally, multidrop mode tries to deduce an envelope address from a
   message before parsing the To/Cc/Bcc lines (this enables it to avoid
   losing to mailing list software that doesn't put a recipient addess in
   the To lines).
   
   Some ways of accumulating a whole domain's messages in a single server
   mailbox mean it all ends up with a single envelope address that is
   useless for rerouting purposes. You may have to set `no envelope' to
   prevent fetchmail from being bamboozled by this.
   
   Check also answer T1 on a reliable way to do multidrop delivery if
   your ISP (or your mail redirection provider) is using qmail.
     _________________________________________________________________
   
M3. I tried to run a mailing list using multidrop, and I have a mail loop!

   This isn't fetchmail's fault. Check your mailing list. If the list
   expansion includes yourself or anybody else at your mailserver (that
   is, not on the client side) you've created a mail loop. Just chop the
   host part off any local addresses in the list.
   
   If you use sendmail, you can check the list expansion with sendmail
   -bv.
     _________________________________________________________________
   
M4. My multidrop fetchmail seems to be having DNS problems.

   We have one report from a Linux user (not the same one as in R1!) who
   solved this problem by removing the reference to -lresolv from his
   link line and relinking. Apparently in some recent Linux distributions
   the libc bind library version works better.
   
   As of 2.2, the configure script has been hacked so the bind library is
   linked only if it is actually needed. So under Linux it won't be, and
   this problem should go away.
     _________________________________________________________________
   
M5. I'm seeing long DNS delays before each message is processed.

   Use the `aka' option to pre-declare as many of your mailserver's DNS
   names as you can. When an address's host part matches an aka name, no
   DNS lookup needs to be done to check it.
   
   If you're sure you've pre-declared all of your mailserver's DNS dames,
   you can use the `no dns' option to prevent other hostname parts from
   being looked up at all.
   
   Sometimes delays are unavoidable. Some SMTP listeners try to call DNS
   on the From-address hostname as a way of checking that the address is
   valid.
     _________________________________________________________________
   
M6. How do I get multidrop mode to work with majordomo?

   In order for sendmail to execute the command strings in the majordomo
   alias file, it is necessary for sendmail to think that the mail it
   receives via SMTP really is destined for a local user name. A normal
   virtual-domain setup results in delivery to the default mailbox,
   rather than expansion through majordomo.
   
   Michael <michael@bizsystems.com> gave us a recipe for dealing with
   this case that pairs a run control file like this:
   
poll your.pop3.server proto pop3:
    no envelope no dns
    localdomains virtual.localdomain1.com virtual.localdomain2.com ...
    user yourISPusername is root * here,
    password yourISPpassword fetchall

   with a hack on your local sendmail.cf like this:
   
#############################################
#  virtual info, local hack for ruleset 98  #
#############################################

# domains to treat as direct mapped local domain

CVvirtual.localdomain1.com virtual.localdomain2.com ...
---------------------------
in ruleset 98 add
-------------------------
# handle virtual users

R$+ <@ $=V . >          $: $1 < @ $j . >
R< @ > $+ < @ $=V . >   $: $1 < @ $j . >
R< @ > $+               $: $1
R< error : $- $+ > $*   $#error $@ $1 $: $2
R< $+ > $+ < @ $+ >     $: $>97 $1

   This ruleset just strips virtual domain names off the addresses of
   incoming mail. Your sendmail must be 8.8 or newer for this to work.
   Michael says:
   
     I use this scheme with 2 virtual domains and the default ISP
     user+domain and service about 30 mail accounts + majordomo on my
     inside pop3 server with fetchmail and sendmail 8.83
     _________________________________________________________________
   
X1. Spurious blank lines are appearing in the headers of fetched mail.

   What's probably happening is that the POP/IMAP daemon on your
   mailserver is inserting a non-RFC822 header (like X-POP3-Rcpt:) and
   something in your delivery path (most likely an old version of the
   deliver program, which sendmail often calls to do local delivery) is
   failing to recognize it as a header.
   
   This is not fetchmail's problem. The first thing to try is installing
   a current version of deliver. If this doesn't work, try to figure out
   which other program in your mail path is inserting the blank line and
   replace that. If you can't do either of these things, pick a different
   MDA (such as procmail) and declare it with the `mda' option.
     _________________________________________________________________
   
X2. My mail client can't see a Subject line.

   First, see X1. This is quite probably the same problem (X-POP3-Rcpt
   header or something similar being inserted by the server and choked on
   by an old version of deliver).
   
   The O'Reilly sendmail book does warn that IDA sendmail doesn't process
   X- headers correctly. If this is your problem, all I can suggest is
   replacing IDA sendmail, because it's broken and not RFC822 conformant.
     _________________________________________________________________
   
X3. Messages containing "From" at start of line are being split.

   If you know the messages aren't split in your server mailbox, then
   this is a problem with your POP/IMAP server, your client-side SMTP
   listener or your local delivery agent. Fetchmail cannot split
   messages.
   
   Some POP server daemons ignore Content-Length headers and split
   messages on From lines. We have one report that the 2.1 version of the
   BSD popper program (as distributed on Solaris 2.5 and elsewhere) is
   broken this way.
   
   You can test this. Declare an mda of `cat' and send yourself one piece
   of mail containing "From" at start of a line. If you see a split
   message, your POP/IMAP server is at fault. Upgrade to a more recent
   version.
   
   Sendmail and other SMTP listeners don't split RFC822 messages either.
   What's probably happening is either sendmail's local delivery agent or
   your mail reader are not quite RFC822-conformant and are breaking
   messages on what it thinks are Unix-style From headers. You can figure
   out which by looking at your client-side mailbox with vi or more. If
   the message is already split in your mailbox, your local delivery
   agent is the problem. If it's not, your mailreader is the problem.
   
   If you can't replace the offending program, take a look at your
   sendmail.cf file. There will likely be a line something like
   
Mlocal, P=/usr/bin/procmail, F=lsDFMShP, S=10, R=20/40, A=procmail -Y -d $u

   describing your local delivery agent. Try inserting the `E' option in
   the flags part (the F= string). This will make sendmail turn each
   dangerous start-of-line From into a >From, preventing programs further
   downstream from acting up.
     _________________________________________________________________
   
X4. My mail is being mangled in a new and different way

   The first thing you need to do is pin down what program is doing the
   mangling. We don't like getting bug reports about fetchmail that are
   actually due to some other program's malfeasance, so please go through
   this diagnostic sequence before sending us a complaint.
   
   There are five possible culprits to consider, listed here in the order
   they pass your mail:
   
    1. Programs upstream of your server mailbox.
    2. The POP or IMAP server on your mailserver host.
    3. The fetchmail program itself.
    4. Your local sendmail.
    5. Your LDA (local delivery agent), as called by sendmail or
       specified by mda.
       
   Often it happens that fetchmail itself is OK, but using it exposes
   pre-existing bugs in your downstream software, or your downstream
   software has a bad interaction with POP/IMAP. You need to pin down
   exactly where the message is being garbled in order to deduce what is
   actually going on.
   
   The first thing to do is send yourself a test message, and retrieve it
   with a .fetchmailrc entry containing the following (or by running with
   the equivalent command-line options):
   
    mda "cat >MBOX" keep fetchall

   This will capture exactly what fetchmail gets from the server, except
   for (a) the extra Received header line fetchmail prepends, (b) header
   address changes due to rewrite, and (c) any changes due to the forcecr
   and stripcr options. MBOX will in fact contain what programs
   downstream of fetchmail see.
   
   The most common causes of mangling are bugs and misconfigurations in
   those downstream programs. If MBOX looks unmangled, you will know that
   is what is going on and that it is not fetchmail's problem. Take a
   look at the other FAQ items in this section for possible clues about
   how to fix your problem.
   
   If MBOX looks mangled, the next thing to do is compare it with your
   actual server mailbox (if possible). That's why you specified keep, so
   the server copy would not be deleted. If your server mailbox looks
   mangled, programs upstream of your server mailbox are at fault.
   Unfortunately there is probably little you can do about this aside
   from complaining to your site postmaster, and nothing at all fetchmail
   can do about it!
   
   More likely you'll find that the server copy looks OK. In that case
   either the POP/IMAP server or fetchmail is doing the mangling. To
   determine which, you'll need to telnet to the server port and simulate
   a fetchmail session yourself. This is not actually hard (both POP3 and
   IMAP are simple, text-only, line-oriented protocols) but requires some
   attention to detail. You should be able to use a fetchmail -v log as a
   model for a session, but remember that the "*" in your LOGIN or PASS
   command dump has to be replaced with your actual password.
   
   The objective of manually simulating fetchmail is so you can see
   exactly what fetchmail sees. If you see a mangled message, then your
   server is at fault, and you probably need to complain to your
   mailserver administrators. However, we like to know what the broken
   servers are so we can warn people away from them. So please send us a
   transcript of the session including the mangling and the server's
   initial greeting line. Please tell us anything else you think might be
   useful about the server, like the server host's operating system.
   
   If your manual fetchmail simulation shows an unmangled message,
   congratulations. You've found an actual fetchmail bug. Complain to us
   and we'll fix it. Please include the session transcript of your manual
   fetchmail simulation along with the other things described in the FAQ
   entry on reporting bugs.
     _________________________________________________________________
   
O1. The --logfile option doesn't work if the logfile doesn't exist.

   This is a feature, not a bug. It's in line with normal practice for
   system daemons and allows you to suppress logging by removing the log,
   without hacking potentially fragile startup scripts. To get around it,
   just touch(1) the logfile before you run fetchmail (this will have no
   effect on the contents of the logfile if it already exists).
     _________________________________________________________________
   
O2. Every time I get a POP or IMAP message the header is dumped to all my
terminal sessions.

   Fetchmail uses the local sendmail to perform final delivery, which
   Netscape and other clients doesn't do; the announcement of new
   messages is done by a daemon that sendmail pokes. There should be a
   ``biff'' command to control this. Type

biff n

   to turn it off. If this doesn't work, try the command
chmod -x `tty`

   which is essentially what biff -n will do. If this doesn't work,
   comment out any reference to ``comsat'' in your /etc/inetd.conf file
   and restart inetd.
   
   In Slackware Linux distributions, the last line in /etc/profile is
biff y

   Change this to
biff n

   to solve the problem system-wide.
     _________________________________________________________________
   
O3. Does fetchmail reread its rc file every poll cycle?

   No. Fetchmail only reads the rc file once, when it starts up. To force
   an rc file reread, do fetchmail -q; fetchmail.
     _________________________________________________________________
   
O4. Why do deleted messages show up again when I take a line hit while
downloading?

   Because you're using a POP3 other than Qualcomm qpopper, or an IMAP
   with a long expunge interval.
   
   According to the POP3 RFCs, deletes aren't actually performed until
   you issue the end-of-session QUIT command. Fetchmail cannot fix this,
   it takes cooperation from the. server. There are two possible
   remedies:
   
   One is to switch to qpopper (the freeware POP3 server from Qualcomm,
   the Eudora people). The qpopper software violates the POP3 RFCs by
   doing an expunge (removing deleted messages) on a line hangup, as well
   as on processing a QUIT command.
   
   The other (which we recommend) is to switch to IMAP. IMAP has an
   explicit expunge command and fetchmail normally uses it to delete
   messages immediately after they are downloaded.
   
   If you get very unlucky, you might take a line hit in the window
   between the delete and the expunge. If you've set a longer expunge
   interval, the window gets wider. This problem should correct itself
   the next time you complete a successful query.
     _________________________________________________________________
   
O5. Why is fetched mail being logged with my name, not the real From address?

   Because logging is done based on the address indicated by the sending
   SMTP's MAIL FROM, and some listeners are picky about that address.
   
   Some SMTP listeners get upset if you try to hand them a MAIL FROM
   address naming a different host than the originating site for your
   connection. This is a feature, not a bug -- it's supposed to help
   prevent people from forging mail with a bogus origin site. (RFC 1123
   says you shouldn't do this exclusion...)
   
   Since the originating site of a fetchmail delivery connection is
   localhost, this effectively means these picky listeners will barf on
   any MAIL FROM address fetchmail hands them with an @ in it!
   
   Versions 2.1 and up try the header From address first and fall back to
   the calling-user ID. So if your SMTP listener isn't picky, the log
   will look right.
     _________________________________________________________________
   
O6. I'm seeing long sendmail delays at start of each poll cycle.

   Sendmail does a hostname lookup when it first starts up, and also each
   time it gets a HELO in listener mode.
   
   Your resolver configuration may be causing one of these lookups to
   fail and time out. Check /etc/resolv.conf and /etc/hosts file. Make
   sure your hostname and FQDN are both in /etc/hosts, and that hosts is
   looked at before DNS is queried. You probably also want your remote
   mail server(s) to be in the hosts file.
   
   You can suppress the startup-time lookup if need to by reconfiguring
   with FEATURE(nodns).
   
   Configuring your bind library to cache DNS lookups locally may help,
   and is a good idea for speeding up other services as well. Switching
   to a faster MTA like qmail or exim might help.
     _________________________________________________________________
   
O7. Why doesn't fetchmail deliver mail in date-sorted order?

   Because that's not the order the server hands it to fetchmail in.
   
   Fetchmail getting mail from a POP server delivers mail in the order
   that your server delivers mail. Fetchmail can't do anything about
   this; it's a limitation of the underlying POP protocol.
   
   In theory it might be possible for fetchmail in IMAP mode to sort
   messages by date, but this would be in violation of two basics of
   fetchmail's design philosophy: (a) to be as simple and transparent a
   pipe as possible, and (b) to hide, rather than emphasize, the
   differences between the remote-fetch protocols it uses.
   
   Re-ordering messages is a user-agent function, anyway.
     _________________________________________________________________
   
   Back to Fetchmail Home Page To Site Map $Date: 1998/03/24 00:04:29 $
   
   
    Eric S. Raymond <esr@snark.thyrsus.com>
