[thelist] subdomains and namespace servers

[tss24 at cornell.edu]

Ok, I have a question, but I don't really know how to 
ask it nor what type of response will help me. So bear 
with me.

Essentially, we have an email server with a couple 
domains. We want to be able to setup subdomains for 
each main domain.

For ex:   joe at joe.com 
Joe logs in, than can alter his email to be:
joe at WHOOHOOO.joe.com

How can I set up this subdomain to properly work with 
the server? I can filter the email to just ignore the 
subdomain and still send all mail to the regular 
account (like a forwarder) easily, but I can't get the 
domain to recognize what server to go to.

Do I need to setup a namespace server? Please help, I'm 
really lost and need a solution soon.

ted