Sendmail: sub-domain masquerade as top level

[Jerahmy Pocott]

Hello,

I'm having an issue with getting sendmail to masquerade
as the top level domain when the host is a sub domain.

For example I want server.exmaple.com to send mail as
user at example.com rather than user at server.example.com,
how ever the masquerade options don't seem to work for
this.. It works fine if the server is a different domain, but
not when it's a sub domain..

How do I get this behavior?

Thanks,
J.