[TriLUG] Looking for the simplest stand-in temporary mail server

[Brian Henning]

> You may need to do it yourself or have a very nice imaginary friend.
If 
> your downtime is greater than x days, the server will start to bounce
the 
> mail.  If you have full control you can set that x variable to a 
> comfortable number to guarantee you don't lose the mail.

"x" should be at most one day and change.  Set up the backup server and
point the DNS to it on Friday afternoon, have the primary server back up
by Saturday evening.

Does proper working of the backup server (with the "relay_domains=..."
setting) depend on multiple MX records?  What I'm not quite sure I'm
grasping yet is how does the backup server know when the primary server
comes back, if there's only one DNS record?  Is there a way to tell the
backup server to not even try to redeliver the mail until I say "ok, go"
through some means?

Thanks a lot,
~B