Tips for moving email to a new server

[biketech]

Hi there.

I'm a newbie administrator for a small non-profit organization. We have about 50 mail accounts on a remote POP server running RedHat 7/Ensim with sendmail. About 25 users are running MS Outlook, downloading messages via POP daily. Several other users using Squirrelmail on about a weekly basis.

Soon, we'll be switching to a new mail server with RedHat Enterprise/CPanel running Exim. My questions are:

- Is there a simple way to handle the period during which DNS refreshes to the new server?

- Specifically, how can I deal with the users who have unread messages on the old server which are not read before the new server is up and DNS is already refreshed?

- Same goes for Outlook users - do I need to set up each person's Outlook to check both the old and new servers until the swith over period is over?

I guess I'm looking for a way to make sure all unread messages on the old server somehow make it to the new server and don't get lost in the shuffle.

Thanks for your help. If you know of an existing thread which addresses this, I'd be glad to check it out.

 

[rouse01]

I recently replaced my office's old redhat 7.3 mail-server with a completely new rh9.0. Here's what I did:

I wanted the new server to have same name as old one, so I don't have to worry about dns.

Installed rh9 on the new box, assigned a temporary ip address (like 192.168.1.3), but used the same hostname as is on my old mailserver. Make sure all services you need are configured (sendmail, pop, iptables, etc) & you have internet connection.

If you don't have this already, install or upgrade Webmin to version 1.15 on both machines.

http://www.webmin.com/download.html

In Webmin, there is an option under the System/Users&Groups that lets you export/import user info. You can set a filter to export UID's greater than, say, 500, which is where all my user ids begin. This will create a file that you can copy to a disk & use to create all the user accounts & passwords, again using Webmin on the new box.

Once you have the users setup on the new box, all you have to do is copy the mail over. You're only a few minutes from done, so I disconnect the old server from the network. I am the only one I know that uses this, but there is a very nice file utility for Linux called Midnight Commander. You can use this from a terminal by typing mc. With it, you can copy & move files, view & set permissions. I used it to copy the users mail to disk, then from disk to the new server. You don't have to copy empty mailboxes from the old machine, since sendmail will automatically create them on the new machine when new mail arrives.

Test your new setup using your own mailbox. You should be able to point your outlook to the new server and pop your mail. Be sure to set your outlook incomming pop to 192.168.1.3 (if you used this ip as temporary).

If you don't have a problem, then reset the new server's ip address to be the old server's ip & you should be done.

In case of catastropy, you can always disconnect the new server & reconnect the old one, like nothing. But I bet you'll have no problems.

Good luck,
Keith