[Mailman-Users] separate smtp server

[JT]

I am trying to set up a mailman installation where the web and smtp
servers are separate... E.g., the list address is mylist at foo.org,
my mail server is mail.foo.org, and the interface is maintained on
www.foo.org

And all of a sudden I'm not sure it's possible, although apparently it
is possible, looking at this very list -- mailman-users at python.org,
mail.python.org, www.python.org!!!

	* Wouldn't each server have to know about the list, and therefor
	maintain their own configurations?  That's obviously a problem.
	How do I avoid it?

	* Or do I just need to do proper mail routing to get this to
	behave?  IOW, the MUA routes list mail to the web server, which
	then "knows" what to do?

I know I'm missing the obvious here, but I just can't see it...  It
MUST be the mail-routing solution, but I can't figure out what goes
where and to what accounts on what servers...  Sendmail-specific
recommendations would be convenient, but any reasonably lucid
explanation of where the mail goes and I'll plod my way through
aliases, virtusertable, etc.

TIA,
JT