On 13 Mar 2019, at 13:25, Shawn Heisey via dovecot <dovecot@dovecot.org> wrote: > * Shut down postfix and dovecot on both old and new servers. > * Updated DNS records to point to new address. > * Ran one final rsync of maildirs from old server to new server. > * Waited 30 minutes with services on both servers still shut down. > * Started postfix and dovecot on new server.
Except for the third minute delay, this is exactly what I did. (I brought the new server up as soon as the sync finished, which was only a few minutes since I'd been syncing frequently. I did leave the OLD server IP offline for awhile after bringing up the new one. I also did not wait 3 days after lowering the TTL which was set to 1 day. I waited about a day and a half, maybe a bit less. What you do not want to do is run the two servers at the same time, which is what it sounded like the OP was intending to do. -- Rincewind had always been happy to think of himself as a racist. The One Hundred Meters, the Mile, the Marathon -- he'd run them all.