We have to replace one mail store (foo.example.org) with another (bar.example.org). I rsync'd the maildirs from foo to bar today and the plan is to hold all delivery (in the SMTP server) on foo over the weekend, rsync again (this time it should be much faster since the large xfer already occurred today), then flush the SMTP queue on foo towards bar, direct all new deliveries to bar.example.org. Users currently access their IMAP mailboxes via imap.example.org. I plan to just 'flip the switch' at DNS so imap.example.org points to bar.example.org (instead of foo.example.org) so users don't have to change anything on their end and should not even notice this change.
Is there anything else I should think about to mitigate users noticing a change? Does the fact that the mail filenames include 'foo.example.org' in the file name (while new deliveries to bar.example.org will include that new hostname) spell trouble later on or can I ignore it? Is there a more efficient way to achieve my goal?
And finally, dovecot on foo.example.org is 1.1.7 while the new server is running 1.1.16. I don't think that should be an issue, but mentioning it just in case.
Thanks!
-- GC