At 10:44 03/05/2003 Wednesday, Stan Horwitz wrote:
 >That log file entry is important. It shows that the message was sent to
 >the recipient's email handler, "xxx.ca". Now, the question remains as to
 >whether or not the system "xxx.ca" routed the mail to the recipient
 >correctly. So now, the recipient needs to contact the administrator of
 >"xxx.ca" and ask why he or she is not receiving email.

Following up on Stan's excellent advice, you might inquire if all MX
hosts and authoritatative DNSes are up to date (or have been changed
within say the last week).

Sometimes I find that DNSes get out of synch, or secondary MX hosts are
no longer accurate for the destination mail server.

These are somewhat difficult to trouble shoot, and even more difficult
convincing the hostmasters and postmasters when there is a problem.

/P