[Dovecot] 0 mails available even if mails in mailbox

[Raphael Thoma]

Hello

We are currently facing the problem, that dovecot doesn't return any 
messages (Pop3: +OK 0 messages) even if there are messages in the cur 
and new directory (maildir format). The logfile does not contain any 
information other than login/logout.

After I deleted the dovecot.index file, all messages are available and 
everything works as expected. According to the wiki page [1] the main 
index file should be synchronized when the cur and new timestamps 
changed. I suppose this synchronization doesn't work correctly because 
the problem still existed after I changed the timestamps manually.

Dovecot version: 10.0.14
Operating System: FreeBSD 7.0-RELEASE-p1
CPU Arch: amd64
Filesystem: NFS
Clients: The problem exists on Pop3 and IMAP. It doesn't matter which 
client. I could reproduce the problem on outlook, thunderbird and even 
on telnet.

Reproduced:

+OK Dovecot ready.
user user at domain.com
+OK
pass password
+OK Logged in.
list
+OK 0 messages:

After deleting dovecot.index:

+OK Dovecot ready.
user user at domain.com
+OK
pass password
+OK Logged in.
list
+OK 20 messages:

It seems to be a problem with the index-file from dovecot which doesn't 
seem to be synchronized.

What could be the reason for this behaviour? How can we fix this issue 
for all customers?

Kind regards
Raphael Thoma

[1] http://wiki.dovecot.org/IndexFiles