Hi, we have two mail servers which are duplicating each other. The have master master replication on the dbispconfig database and glusterfs running on th var vmail to keep all files in sync. IMAP and POP3 (I believe) connections are handled through courier. The issue I have is if for some reason we have to change a user from accessing their mail on one server to accessing it on the other server there is a reasonable chance that they will get duplicate emails from some weeks ago. Also if we have to restart a server they are logged onto they may redownload all emails on that server. The users having the issue have all selected the leave messages on the server option. Have we set up a redundant mail server in the right way or should we be doing things diferently? All help appreciated and extra info can be provided where required.