I am going to move a site with about 12 email accounts. I am considering the best way to do this to minimize the impact on my client and also the easiest way for me as well.
I am considering doing it late at night, to minimize emails messages ending up at the old server I was wondering if this method would work.
Copy all the email accounts to the new server.
Delete the email accounts
Flip the DNS to the new server
This way any emails sent while DNS propagation is still happening will be held and then delivered when propagation is complete, resulting in no emails left on the old server. I realize the flaw in this plan is the amount of time it takes for propagation, it seems to happen pretty quick these days so think it could work quite well.
I would like to here others thoughts on this or perhaps a better way to handle it.