Yeah, that smells bogus. You can't send the EXPUNGE right away, even if you did the EXPUNGE. As the server you're required to wait for a command which allows expunges to happen. I've double-checked the Cyrus IMAP server, and we check usinguid to decide if we can tellexpunge at the end of index_store - aka, only UID STORE will tell the client EXPUNGE responses. Unfortunately, this is a pretty common way in which IMAP servers are non- compliant - immediate EXPUNGE combined with incorrect telling of EXPUNGE responses. Having said that, fetchmail is also wrong here:

fetchmail: IMAP> A0008 STORE 1 +FLAGS.SILENT (\Seen \Deleted) fetchmail: IMAP< * 1 EXPUNGE fetchmail: IMAP< A0008 OK Store completed fetchmail: IMAP> A0009 EXPUNGE fetchmail: IMAP< A0009 OK EXPUNGE completed fetchmail: mail expunge mismatch (0 actual != 1 expected) There is no guarantee that you would get exactly 1 from the EXPUNGE command. You could easily have had other messages marked \Deleted, or even this same message get the \Deleted flag removed by another session in the gap between A0008 and A0009. the EXPUNGE could return any response between zero and the number of messages in the mailbox. In theory, the number of messages could even have been increased and then the EXPUNGE removed more than the previous mailbox size all at once! Bron.

On Sat, Dec 16, 2017, at 04:18, Kamil Jońca wrote:

(This is not neccesarily about dovecot, but rather IMAP protocol)

At https://drive.google.com/open?id=1j3oa5jYeSdiPbgaihq02K-u_vHbZLJZQ> is fetchmail log from my sessinon with polish email provider "Wirtualna> Polska" As you can se fetchmail logged "* 1 EXPUNGE" as a response to "STORE"> command. According to https://tools.ietf.org/html/rfc3501#section-7.4.1 EXPUNGE must not be sent as response to STORE command. Am I right that their imap server is erroneous or am I missing something? KJ

-- http://stopstopnop.pl/stop_stopnop.pl_o_nas.html Lonely men seek companionship. Lonely women sit at home and wait. They never meet.

-- Bron Gondwana brong@fastmail.fm