🚀 go-pugleaf

When I use Xrn (X based news reader) on a Sparc station running SunOS 4.1.1 to
forward newsgroup posts the From: field of the mail message gets messed up. 
Generally what happens is that the mail is addressed as coming from the
receipents, and not from me.  (I've seen even stranger behavior running
on an NIS client where the receipient wasn't in the local /etc/passwd file,
namely the From: field simply got the last entry in the local /etc/passwd file!)

sendmail is invoked from xrn as a pipe with the arguments /usr/lib/sendmail -oi
-t and the message is piped into sendmail.

The really strange thing is that this only happens if I start xrn from the twm
menu and not if I start it from a shell in my xterm.  I've checked the
environment variables for shells that twm starts and I've gone through enough of
the execution of xrn with a debugger to be satisfied that /usr/lib/sendmail is
getting a correct message in both cases.  It seems to me that the
/usr/lib/sendmail sub-process must be behaving in a subtly different way
depending on how the xrn program is started.

What is causing this strange behavior?

Thanks,
--dan