Hi,
I use Kmail 1.13.0 to read my emails on an Exchange 2007 IMAP server.
I can retrieve all emails, but when I decide to erase some of them, they are disappearing from my view, but re-appearing if I check new emails.
Messages are not actually purged on the server.
Note that I've checked the automatic purge of messages. Even if I force purge, messages appear again.

Is it a known bug ? Can I fixe it ?

I know that Exchange IMAP server has not been fully supported in the past, which probably explains your problem. I also know that a good deal of work has been done regarding this. What I don't know is the current status of that. It would be a good idea to ask on the kdepim mailing list, where Ingo reads and would probably be able to tell you.

Some years ago it was revealed that quite a lot of servers do not purge emails immediately; so it could be a function of your IMAP server provider as well.

i don't know if that helps at all, but i had a similar problem with gmail. deleted emails remained on server in the archive (all mail folder). i had to move every message to the trash folder (not local trash! the one on imap) then sync imap (emails get 'moved' to trash on server) and then empty trash. after a final sync the emails are gone.

Thanks everyone for your help.

It seems that I can't even move an email into an imap folder.
I've tried with kmail 1.12 and kmail 1.13.

If Kmail doesn't handle well IMAP (ie Gmail and Exchange), maybe I need to post a bug.
Do you know where I can do that ?

bugs.kde.org should be the place

Please note that KMail will hopefully be moved to Akonadi based infrastructure in KDE 4.5, which includes completely rewritten IMAP support.