My old mail system is a non zimbra imap/pop3 server called mail.mydomain.com my new email server is a zimbra server we are trying to move over to. We have out new zimbra server called newmail.mydomain.com we have the mx records pointing to newmail.mydomain.com and all new mail is now arriving at the new zimbra server. We changed the dns of mail.mydomain.com to now point to the ip address of the zimbra server (newmail.mydomain.com)... We thought this would be transparent to the users however the can login and authenticate but will no see any mail. However if we point them to use newmail.mydomain.com it works fine even though mail.mydomain.com and newmail.mydomain.com are both pointing to the same ip address. However on the newmail.mydomain.com authenticated sessions will show imap mail. Needless to say we had to change the dns to point the mail.mydomain.com back to the old email server until we figure out why this is not working. Anyone have a clue?