You may have problems if you're using DNS only.
If your going to do it this way you probably want to make sure resolv.conf line for hosts says "files dns" and make sure your host file on each machine is correct.
I'm assuming the domain's MX record will point to the old machine until you've migrated everyone.
We're planning it a little differently. We have an MX record for the old machine as the domain. The MX record for the new machine is the new machine only. When we're ready we'll turn the MX domain record over to the new machine and use a CNAME record for the old mail server name to point to the new server.
This gets around the DNS issues. |