[Mimedefang] Re: best way to do this?

[Jeremy Mates]

* Douglas J Hunley <doug at hunley.homeip.net>
> I'm moving some addresses from our old server (smtp.companya.com) to
> our new server (mail.companya.com). I'm gonna have 'mail' listed as
> the secondary MX for right now (leaving 'smtp' as the primary) and was
> thinking of using MD to return a tempfail for groups of email
> addresses to force the sending MTA to fail-over from 'smtp' to 'mail'

I usually end up putting a mailertable entry on the old server to shunt
all e-mail over to the new server, after confirming that the new server
will indeed accept e-mail destined to the old one properly.

On old server in mailertable file, with mailertable support in
sendmail.cf:

.example.com	esmtp:[mail.example.com]
example.com	esmtp:[mail.example.com]

If transfering user mailboxes, run the daemon on the new server in queue-
only mode, and use another runner to periodically deliver local e-mail
(but not while the mailboxes are being moved! :). On the port-25-
listening daemon, set the following in its .mc file:

define(`confDELIVERY_MODE', `deferred')