procmail

My first guess: if you have a home directory on the sparcstation, but a .forward file and procmailrc there. procmail is pretty good about being transparent for delivery. If you have an empty .procmailrc file, it should dump everything right back in your spool file. You can look at the last Received line in your incoming mail to determine what machine the last sendmail is running on. Your binary should go on that machine, I think. Eric