I am not certain that this has something to do with SpamSieve, but it might.
My client has an Xserve with SpamSieve running on Mail.app. All the household mail accounts are hosted externally on a Linux server that they also control. They all use IMAP for their mail, and all accounts are set up within Mail.app on the Xserve. The only reason for this is SpamSieve. That machine gets all mail, filters spam. So when they check their mail on the Linux server from another Mac or an iPhone, the spam should be filtered out.
Problem is that once in a while, the spams just goes into a long loop. They get downloaded to the Xserve, they get filtered and correctly marked as spam, moved to the SPAM folder. But, they are not signed out from the Linux server. So the next minute the Xserve checks for mail, it will again find the same mail, classify as spam, move it to SPAM folder, but again, will not sign it out. The SPAM folder keeps copies upon copies of these mails, all with the same time-stamp. A day would normally bring about 5-7000 emails into that folder.
I can select all mail there and hit delete. Again, they are not deleted from the server. On the next fetch, a new copy will be downloaded.
Where does her problem reside? The only solution is to actually delete the account from the Linux server and create it again as a new account. That defeats the purpose of IMAP, where she wants the archive of all mail to stay accessible on the server. All is deleted.
Woul appreciate any help you could offer. My client is frustrated.