Sendmail and masq

[David Benigni]

I recently setup a machine as mail server running Fedora.  The
interesting thing is I don't have any of the masq'ing options enabled. 
However, I have another linux machine that sends mail out as
root at localhost.localdomain and when it passes through the Fedora box its
rewriting the domain from localhost.localdomain to the hostname.domain
of the Fedora box.  Has anyone saw this and know why?  I'm confused
since all the masq'ing options are commented out and the cf file
recreated.  TIA.

Dave