[ale] Sendmail Proxy between internet and NT 4.0 with Exchange 5.0

[Joe]

I found out the hard way about Exchange V5.0 and 
the NDR UCE/spam issue. And I'm not gonna suggest upgrading Exchange to fix the 
issue either.
 
I want to configure a sendmail machine to receive 
the mail and then forward legitimate mail to Exchange.
 
 
I have a fresh install of slackware 8.1 on a 
machine ready for configuration.
 
Can someone point me in the right 
direction?
 
thanks
 
 
Joe