Hi,

we have encountered an interesting behavior with users that have their mailboxes over quota while having sieve-vacation enabled. We do a temp fail, if a mailbox is over quota.

Problem:

If a remote sender sends an email to such a user (over quota + vacation), Dovecot directly creates a response message and sends it back to the sender. So far so good. At the same time the original email cannot be stored in the users INBOX, which leads to a temp fail action. Now the email remains in a queue and whenever the queue manager tries to deliver the email again, the behavior starts again. Send vacation response and temp fail, until either the queue life time exceeds or the user has cleaned up his/her mailbox and the message can be stored.

For the remote sender it means getting lots of vacation emails from the same recipient. For each retry one vacation message.

Tracing:

We dig a little bit deeper and turned on logging to see what happens.

Because the email cannot be put into the users INBOX, it keeps in a failure state. And because of this, the dupes-file is not updated for this particular sender.

We are not sure, if this is a wanted behavior or not. But for a sender, it is really annoying to receive vacation messages on and on.

Solution:

Unfortunately we could not find any settings to change this. So I come here and ask for your kindly help. At the moment of this writing I can not provide a doveconf -n output, but I hope you trust me that we have not done too many things wrong ;-)

Christian Rößner

Rößner-Network-Solutions Zertifizierter ITSiBe / CISO Karl-Bröger-Str. 10, 36304 Alsfeld Fax: +49 6631 78823409, Mobil: +49 171 9905345 USt-IdNr.: DE225643613, https://roessner.website PGP fingerprint: 658D 1342 B762 F484 2DDF 1E88 38A5 4346 D727 94E5