Cyrus IMAP Server FAQ

• Using PAM Under Linux when using PAM and shadow passwords, /etc/shadow needs to be readable by the Cyrus user.
• POP-Before-SMTP It is not included in the default distribution because there is already a standard way of doing this with SMTP AUTH. Any good MTA and/or MUA should support SMTP AUTH, so we shouldn't have to create a hack in an unrelated service. However, if you would like to install it anyway, we recommend using DRAC, along with the patch available in contrib/drac_auth.patch.
• Using NFS We don't recommend it. If you want to do it, it may possibly work but you may also lose your email or have corrupted cyrus.* files. You can look at the mailing list archives for more information.
• Using AFS/Coda We don't recommend it. It's even less likely to work than NFS. If you want to do it, it may possibly work but you may also lose your email or have corrupted cyrus.* files. CMU's previous e-mail system, AMS, leveraged AFS extensively for storage (and transit) purposes. For various reasons it didn't scale particularly well and led to CMU's interest in IMAP.

  Cyrus was designed to use a local filesystem with Unix semantics and a working mmap()/write() combination. AFS doesn't provide these semantics so won't work correctly.

• Virtual hosting - This will be supported starting in Cyrus 2.2.
• dots in userids - you can have a '.' in your username IF, AND ONLY IF, you use the UNIX hierarchy convention.
• renaming users - nope, not supported.
• plus addressing
• Performance/Capacity/Scaling - See the performance guide.

Troubleshooting

Q: I'm getting syslog'd messages from the master process saying processes are "signaled to death by 10". What's up?

A: If you're using Berkeley DB 3.0.55, try installing some patches to Berkeley DB available from http://www.sleepycat.com/update/3.0.55/patch.3.0.55.html.

Q: I've used saslpasswd2 to create CRAM-MD5 secrets, but imapd doesn't say AUTH=CRAM-MD5. Why?

A: Make sure /etc/sasldb2 is readable by the Cyrus user.

Q: I'm using "sasl_pwcheck_method: saslauthd", but authentication isn't working.

A: Make sure that the saslauthd daemon is running (you'll want to start it when the system boots). imapd is unable to connect to saslauthd if the following message appears in the logs:

Dec  6 12:58:57 mail3.andrew.cmu.edu imapd[1297]: cannot connect to saslauthd server

Make sure that saslauthd is running and that the cyrus user can access the unix domain socket (defaults to /var/run/mux).

Q: I'm getting messages about "duplicate_prune". What's wrong?

A: These messages look like

Jan 14 13:46:24 grant ctl_deliver[9060]: duplicate_prune: opening
  /var/imap/deliverdb/deliver-x.db: No such file or directory
Jan 14 13:46:24 grant ctl_deliver[9060]: duplicate_prune: opening
  /var/imap/deliverdb/deliver-y.db: No such file or directory
Jan 14 13:46:24 grant ctl_deliver[9060]: duplicate_prune: opening
  /var/imap/deliverdb/deliver-z.db: No such file or directory

These messages are normal; one file is maintained for each user beginning with "x", "y", "z", etc. If you're first starting or you have no users beginning with these letters, these messages are completely normal and can be ignored.

Q: I'm getting a message about "imapd: could not getenv(CYRUS_SERVICE); exiting" in my imapd.log. What's wrong?

A: Remove all imap, pop, lmtp and sieve lines from [x]inetd.conf and restart [x]inetd.

Q: How do I use different SSL/TLS certificates for imap and pop?

A: Specify the different certs using the appropriate options in imapd.conf. Read imapd.conf(5) for details.

Q: My KPOP client is complaining about TLS keys. What should I do?

A: Disable TLS for the kpop service. Either set tls_pop3_cert_file to disabled in imapd.conf (which will also disable SSL/TLS for pop3), or use a separate config file for kpop. For example, change the kpop service in cyrus.conf to something like:

kpop    cmd="pop3d -k -C /etc/kpopd.conf" listen="kpop"

then copy /etc/imapd.conf to /etc/kpopd.conf and remove the tls_* options.

Q: Eudora 5.x can't connect using STARTTLS ("SSL Neogotiation Failed"). What should I do?

A: First, complain to QUALCOMM because their STARTTLS implementation is broken. Eudora doesn't support TLSv1 (per RFC2246) and Cyrus requires it. If you really need this before it is fixed in Eudora, remove or comment out the following lines in tls.c:

    if (tlsonly) {
        off |= SSL_OP_NO_SSLv2;
        off |= SSL_OP_NO_SSLv3;
    }

Q: I'm getting messages in imapd.log like:

Sep 11 17:23:55 ogg lmtpd[773]: DBERROR db3: 16 lockers
Sep 11 17:23:55 ogg lmtpd[1409]: DBERROR db3: 17 lockers
Sep 11 17:23:56 ogg lmtpd[1508]: DBERROR db3: 9 lockers
Sep 11 17:23:56 ogg lmtpd[776]: DBERROR db3: 9 lockers

What's wrong?

A: Nothing is wrong. These messages are logged whenever Berkeley db encounters lock contention, but isn't necessarily a problem by themselves. This is especially likely when you have an empty or small duplicate delivery database and are receiving a large volume of e-mail.

Berkeley db 4.0 has a bug where the number of lockers isn't decremented properly, causing this number to be unreliable.