Masquerading Virtual domains in sendmail

[Gayn Winters]

I'm installing sendmail.8.13.3 on FBSD 5.4 on node.domain1.com.  

I've configured /etc/mail/local-host-names to accept mail for
domain1.com and domain2.com.  

My user names look like bob.domain1.com and (a different Bob)
bob.domain2.com.  

Inside /etc/mail/virtusertable I map
bob at domain1.com	bob.domain1.com
bob at domain2.com	bob.domain2.com

Inbound all is well. BUT, 

What I can't figure out is how to masquerade mail from bob.domain1.com
as being from bob at domain1.com AND ALSO HAVE bob.domain2.com masqueraded
as being from bob at domain2.com.

One test of this working is to be able to register both Bob's in the
FreeBSD mailing lists as bob at domain1.com and bob at domain2.com.

Ideas? References?

Thanks,

-gayn

Bristol Systems Inc.
714/532-6776
www.bristolsystems.com