We're wanting to implement a new SMTP server and install it on an AS/400. Here's the current architecture:
Mail destined to the internet routes directly to a sendmail server and out to the Internet.
Affiliates send mail through an existing SMTP is an AIX server. That sends to the sendmail server and out to the internet.
All inbound mail routes through the sendmail server to the AIX SMTP server and on to the respective mail server. The problem that I'm running into is because we let Domino handle the SMTP routing and the network engineers don't seem to understand that Domino does its own SMTP mail routing. They're hung up on the fact that they can't telnet over port 25 to that server.
My question: Should I have SMTP enabled for the AS/400?
According to the architecture you described, it sounds like you will want SMTP enabled on the AS/400. However, you may also want to relay all mail to the SendMail server. Use the "Relay Host" field in the configurations document for that server.
This was first published in August 2002