sendmail problems - any experts out there?

[Peter Steele]

I'm having a sendmail problem for which I've not been able to come up with
an adequate solution. When I send mail out from either of two separate Unix
systems we have here (a Sun 4/280 and a CDC 4680) the "From:" line generated
by sendmail is insufficient for recipients to use in replies. For example,
if I mail from my Sun account to some site outside of Acadia, the "From:"
line looks like this:

    From: peter at aucs (Peter Steele)

where aucs is the host name of the Sun 4. When the recipient tries to reply
to this message, sendmail assumes aucs is the name of a machine in its
domain and consequently fails to delivery the mail as it should. The correct
"From:" should include our domain:

    From: peter at aucs.acadiau.ca (Peter Steele)

This behaviour is exhibited on both of our Unix machines. Although I have
made several changes to my sendmail.cf file, none are completely adequate
to solve this problem. Furthermore, I have talked to other sites with
virtually identical sendmail.cf files who do not have this problem, and
others who do (including CDC tech support). If anyone has some idea what
is causing this problem I would appreciate hearing from you. Thanks.

Peter Steele, Systems Software Analyst
Acadia University, Wolfville, NS Canada
Internet: Peter at aucs.acadiau.ca
Voice: 902-542-2201-121