There are lots of little bits of knowledge you need to know to get started. Here I attempt to catalog them.
User mailboxes live under 'user.<username>'. To the user, this mailbox is called simply INBOX; sub-folders such as 'user.<username>.Sent', appear to the user as 'INBOX.Sent' (NB: altnamespace).
Cyrus IMAP's mailbox storage is not Maildir, although it is similar in some respects. You should not expect to access the mailboxes directly as you might other servers; only access messages through POP3 or IMAP.
The mailbox storage does use databases, but it cannot use SQL. People occasionally ask about using SQL, but it does not seem to be an appropriate use of SQL; the data is not especially relational. The data is hashed for fast lookups, which is better done by file-based databases when data is not relational. Most people who are ask about SQL storage have high-availability in mind, which is easy with certain databases (like MySQL); most highly-available Cyrus implementations use SANs and clustered filesystems.
Mailboxes have to be created before being used, either with 'cyradm' or another tool (NB: autocreate patches).
Deleting a message in IMAP requires two steps: First, set the \Deleted flag on the message. Second, EXPUNGE the mailbox. Many MUAs first move messages to a Trash folder, but given the recoverability inherent in a two-step deletion, it is generally considered a design flaw of the MUAs.
Cyrus IMAP logs to syslog facility local6 by default, but can
be overridden at compile-time. (Simon Matter's RPMs default to the
mail facility.) To configure logging, add a line like the following
to your /etc/syslog.conf:
local6.info /var/log/imapd.log
The usual rules for syslog.conf apply;
you must use tabs and not spaces. If your platform, such as
Solaris, requires the log file exist before syslogd will write to
it, you must create it. Finally, you must send syslogd the HUP
signal to make it reload its configuration or restart it.
You might also want to have it log to the same file as the mail facility. If you do not want to recompile, just change the line in for the mail facility to include the local6 facility, such as the following:
mail.info;local6.info /var/log/maillog
Your messages log might have a wildcard facility, so you should exclude local6 from that by changing it to be similar to the following:
*.info;mail.none;authpriv.none;cron.none;local6.none /var/log/messages
If you want more messages, change "info" to "debug", but be warned that some of the debugging messages are informational and might not be generally cause for worry if you are not experiencing problems.
As a debugging aid, Cyrus IMAP can also log protocol conversations on a per-user basis. Note that you cannot debug the authentication process using this, because the protocol logging is only associated with a username and until a user has been successfully authenticated, the username is unknown.
To enable protocol logging, simply create a directory in
/var/lib/imap/log with the user's name you
wish to log. Ensure, of course, that this directory is writable by
the user Cyrus runs as. Cyrus will create files in this directory
with the name of the process ID under which it runs (which changes
per connection due to the forking server model it uses).
# cd /var/lib/imap/log/
# mkdir wcooley
# chown cyrus wcooley/
I've created the directory and now I'm logging in with a mail client, which selects my INBOX, checks messages and ACLs and logs out.
# pwd
/var/lib/imap/log/wcooley
# ls
30069
# less 30069
---------- wcooley Thu Feb 17 11:20:35 2005
>1108668035>a0001 OK User logged in
<1108668035<a0002 LIST "" ""
>1108668035>* LIST (\Noselect) "." ""
a0002 OK Completed (0.000 secs 0 calls)
<1108668035<a0003 SELECT "INBOX"
>1108668035>* FLAGS (\Answered \Flagged \Draft \Deleted \Seen)
* OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen \*)]
* 0 EXISTS
* 0 RECENT
* OK [UIDVALIDITY 1107062834]
* OK [UIDNEXT 1]
a0003 OK [READ-WRITE] Completed
<1108668035<a0004 MYRIGHTS "INBOX"
>1108668035>* MYRIGHTS INBOX lrswipcda
a0004 OK Completed
<1108668035<a0005 NOOP
>1108668035>a0005 OK Completed
<1108668042<a0006 CLOSE
>1108668042>a0006 OK Completed
<1108668042<a0007 LOGOUT
>1108668042>* BYE LOGOUT received
a0007 OK Completed