We've been using dovecot for a while now (currently 1.0beta7) and it works nicely. We have just one reoccuring problem:
When using thunderbird as the imap client sometimes when messages are moved from the inbox to other folders (including Trash) they shortly thereafter reappear in the inbox - this can happen multiple times to the same message. We have multiple namespaces set up so that inbox is mbox format in ~/.poffice/username and other folders are maildir in ~/Maildir - both of these are on NFS. Indexes are on local storage. The problem only seems to happen with thunderbird. kmail, mac mail, outlook, pine all work fine. If we effectively move a user so that their inbox is also maildir then the problem doesn't happen. The inbox being mbox format is for historic reasons and medium to long term this should change to maildir but in the interim can anyone see anything different that thunderbird does to other imap clients that might be tickling an underlying bug?
cheers mark