[Dovecot] thunderbird and email duplication

[Alexander Banthien]

Hi all,

I have recently switched over to Dovecot from CourierIMAP trying for 
some speedup, which I did get. Installation went OK, so all seemed fine.

But suddenly I realised, that incoming emails are replicating 
themselves. This seems only to happen when connected with Thunderbird. I 
am also using Squirrelmail and KMail as clients which don't seem to show 
the behaviour.
It seems to happen only for mails received during a Thunderbird session. 
When I close TBird and reopen it, only newly received messages will show 
the funny behaviour.
The emails are real file copies in the Maildir, I have checked that.

Running Dovecot on Debian Etch: dovecot --version: 1.0.0 (this is Debian 
package 1:1.0.0-1~bpo.1 from backports. I have tried the main package 
from Debian aswell, same result) with qmail delivering the mails to a 
Maildir without Dovecot's LDA.
Clients:
Thunderbird 2.0.0.6 on WinXP over Wireless LAN (tried 
Thunderbird/Iceweasel on Debian aswell)
Squirrelmail and KMail (both running on the same box as Dovecot) don't 
show that behaviour.

Has anybody seen anything similar or have any advice on what to look 
for? I would like to stick with Dovecot but the way it is looking now, I 
find working with emails near impossible.

Thanks in advance,

Alexander

-- 
---------------------
Alexander Banthien
ParentPay Ltd.
Project Manager
+44 1926 812704 (o)
+44 7787 562694 (m)
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