[NTLUG:Discuss] Secondary Mail Server

[Rev. wRy]

I recently got a second box to use as a secondary mail server for one of 
my domains, and have a question as to the setup.  Recently, my primary 
server went down, and the secondary box did it's job and caught all the 
mail, but it didn't forward to the primary box when it came back up.

1)  What needs to be configured to make this happen automagically in 
sendmail?  I have a feeling I borked an entry in my local-host-names 
file, but I'm not sure.

2) I have created the virtualuser table with local users on the 
secondary box mapped to the users on the first box in this fashion:

localuser1	localuser1 at primary.mailserver.com

Is the above the way that should be handled?

TIA-
Ry