Migration woes...Imap working one way

[jbuwa]

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?

[Krishopper]

If you're using IMAP, you may need to have them refresh their IMAP subscribed folder list on their email clients after you change the IP address? I'm not too sure how the IMAP subscriptions work, since I have never dug too far into the technical details of it.

[jbuwa]

Well here is what I found. If you set the client to the mail.mydomain.com and login you authenticate but no messages. Set the client to newmail.mydomain.com authenticate get messages and switch the server name back to mail.mydomain.com and login again it works fine past this point. However walking 600 clients into switching server names in there client program and back again defeats the whole purposed and you might as well tell them to change the server name anyhow. I wanted to this to be transparent on there end which is why I did the dns changes. Also removing the login info from the client programs and putting it back in again with the mail.mydomain.com still did not work. Frustrating.

[bdial]

have you verified that the clients are actually hitting the new server, and not caching the ip of the old one?

[jbuwa]

yes and even if you specify ip address and not the actual server name newmail.mydomain.com it wont work unless you get there by exactly newmail.mydomain.com