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

   Back to Fetchmail Home Page To Site Map $Date: 1997/10/20 16:51:41 $
     _________________________________________________________________
                                      
                  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?
   
                             Build-time problems:
                                       
   B1. 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?
   
                           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?
   
         Configuration tips for non-sendmail MTAs and unusual servers.
                                       
   T1. How can I use fetchmail with qmail?
   T2. How can I use fetchmail with exim?
   T3. How can I use fetchmail with smail?
   T4. How can I use fetchmail with SCO's MMDF?
   T5. How can I use fetchmail with Lotus Notes?
   T6. How can I use fetchmail with Microsoft Exchange?
   T7. How can I use fetchmail with Compuserve RPA?
   T8. How can I use fetchmail with HP OpenMail?
   
                             Runtime fatal errors:
                                       
   R1. Fetchmail isn't working, and -v shows `SMTP connect failed'
   messages.
   R2. When I try to configure an MDA, fetchmail doesn't work.
   R3. Fetchmail dumps core when given an invalid rc file.
   R4. Fetchmail dumps core in -V mode, but operates normally otherwise.
   R5. Fetchmail dumps core when I use a .netrc file but works otherwise.
   R6. Running fetchmail in daemon mode doesn't work.
   
                               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?
   
                                   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 it 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.
   
   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.
   
   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. 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. 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 (October 1997) no OTP or APOP-like facility
   generally available on IMAP servers.
   
     _________________________________________________________________
                                      
G9. Is any special configuration needed to use a dynamic IP address?No.
Fetchmail itself doesn't care whether the IP address you use is static (fixed)
or dynamic (varying, allocated at connection time by your ISP from an address
pool). In fact, fetchmail normally doesn't use your address explicitly at all;
it only cares that you have a working gateway.

Only one fetchmail option interacts with your IP address at all, `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.

  __________________________________________________________________________
                                       
B1. 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 since 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)

in order to migrate. 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 two 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.

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.

  __________________________________________________________________________
                                       
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 ', where 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 pop3:
        preconnect "ssh -f -L 1234:mailhost:110 mailhost sleep 20 /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"

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 Aman, who has documented more of sendmail then I can
digest! The actual setup I used though was by David Begley, who has put
together a WWW page describing how to quickly implement these rules yourself.

http://www.nepean.uws.edu.au/users/david/pe/blockmail.html

David's pages could be moving shortly. I will post an update if it happens.

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 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.

  __________________________________________________________________________
                                       
T2. 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).

  __________________________________________________________________________
                                       
T3. 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.

  __________________________________________________________________________
                                       
T4. 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.

  __________________________________________________________________________
                                       
T5. 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'.

  __________________________________________________________________________
                                       
T6. 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.

  __________________________________________________________________________
                                       
T7. 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.

  __________________________________________________________________________
                                       
T8. 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.

  __________________________________________________________________________
                                       
R1. 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. 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.

  __________________________________________________________________________
                                       
R2. 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 linking
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.

  __________________________________________________________________________
                                       
R4. 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).

  __________________________________________________________________________
                                       
R5. 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.

  __________________________________________________________________________
                                       
R6. 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.

  __________________________________________________________________________
                                       
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 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 wayThe 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 doen'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.

  __________________________________________________________________________
                                       
Back to Fetchmail Home Page To Site Map $Date: 1997/10/20 16:51:41 $


    Eric S. Raymond <esr@snark.thyrsus.com>
