The problem is in receiving mail. The line in the log that I'm having trouble deciphering is:
02627 >>> 550 5.0.0 Access denied
This is coming from sendmail on my box (listed as xyz.com). It seems that sendmail can't write something to somewhere but I'm not sure exactly what or where.
550 is an smtp error code basically saying "I can't do that" the 5.0.0 is a mystery.
As for my obstinace for sticking with sendmail -- the reasons are many and varied. I'm not going to go into it here.
Cliff