[SM-USERS] Using sendmail with SM

[Scott H. @ B. P. <Sco...@bu...>]

When I first set up SM, I used it's own MTA to send out the mail, via a
gateway mail server.  Then for kicks I tried sendmail.  I was surprised to
see it took 1/3 as long to send mail this way - at least it appears that way
to the user, since it takes 10 seconds instead of 30 to get back to the next
screen after hitting "Send".  So I like this, and I want to hand off mail
handling to sendmail.  Now I know this is simple, but I can't get something
configured right.  I searched our list, and headed over to sendmail.org and
etc., but I still haven't got it.  Since this would seem a common SM
configuration, let me ask here... 

I just want sendmail to do 2 things:  

1. any mail addressed without a domain should get a specified domain name
appended to it.

2. all outbound mail gets sent to the gateway mail server for relay

How do I do this?