🚀 go-pugleaf

I'm having the hardest time getting SENDMAIL's sendmail.cf file configured
right and getting the mail headers straight.  When mail is sent OUT of our
"domain" (geo.brown.edu), everything is fine.  But, when mail is sent WITHIN
our domain with a hostname (Fully qualified or not), it get mangled with
something like robinson@PGGIPL.porter.geo.brown.edu.  'porter' being our
mailhost.

I know it's because I have a Dm in the sendmail.cf file (sc) that explcitly
states Dmporter.geo.brown.edu, but I did this because if I don't have it...
the From: address becomes something like robinson@geo.brown.edu to
external mail.  

So the question is... Either how do I get the PGGIPL.porter.geo... problem
fixed, or how can I define a mailhost for geo.brown.edu so that external
hosts connecting to us can resolve geo.brown.edu to our mailhost which is
porter.geo.brown.edu.

Thanks!

Darrin

P.S. Another related question... would using sendmail.mx work... we have
     MX records defined in our Name Service?

 .  Darrin E. Robinson (DER31)         Hamnet   N1LLV  146.700-, 146.880= MHz
/|  Systems Programmer II              Internet darrin@mit.edu
\|  Dist. Computing & Network Services          robinson@porter.geo.brown.edu
 |\ MIT Information Systems            ICBMnet  41 29 24 N  71 18 48 W (NPT)
 |/ 1 Amherst St. - Rm E40-338         Nasamail derobinson@nasamail.nasa.gov
 .  Cambridge, MA 02319                AT&Tnet  (617) 253-0131