[Dovecot] Dovecot truncating Inboxes?

[Harald Strack]

Hi,

Environment:
>10000 Users (LDAP)
Solaris 10 / sparc
imap: dovecot-1.1.10 (pam-unix, no direct LDAP access)
pop: dovecot-1.0.14 on another server (pam-unix, no direct LDAP access)
mta: postfix (pam-unix, no direct LDAP access)
procmail (pam-unix, no direct LDAP access)

Filesystems:
Inboxes and IMAP-home are on two different SAM-FS volumes.

Problem description:
Inboxes of users are disappearing / are truncated. 

we are using dovecot-1.1.0 since two month as main IMAP server. It
replaced our long running but old version of UW-IMAP. Till the last week
we had no problems and it worked quite well and the whole mail system
worked in this configuration since several years. But since a week we
receive more and more complaints regarding truncated/deleted mailboxes.
First, we assumed user/client errors, but as such messages arrive more
frequently, we did a deep analysis of the issue. 

The only common component of our mail system (postfix (local), procmail,
pop, imap) that all concerned users have accessed, was dovecot-imap v.
1.1.10. 

We have no locking problems, we use fcntl(), dotlock for all mail
components. We tested this with a small perl script and locking works
fine (no delivery to a locked mailbox and so on...)

Finally, all indications point to a bug in dovecot. Google and searches
in this mailing list did not come up with any valuable results.

Are there any known bugs / configuration problems concerned to the
described problem?

I greatly appreciate any help!

Thx in advance

Harald Strack