Configure Exchange 5.5 For Sub-Domains

How do I setup a subdomain on Exchange 5.5?

Example: Right now exchange is installed on Server1 so email is going through this server. I also have Server2 with Sendmail. How do I configure exchange so that email for john@server2.mycomp.com will be pointed correctly to Server2, where John will use POP to retrieve his mail? Without any subdomain configuration, Server1 seems to get confused and just bounces the message back to the sender.

Advice and instructions would be gladly appreciated.

Thank you.