We have a bastion host running Digital Firewall for
UNIX v2.0 with smtpxd v1.7 (a wrapper for sendmail)
and sendmail 5.65v3.2. We are also running BIND
v4.9.3 on this same machine.
Periodically, some messages are returned by sendmail
with the following error message:
>550 lists.teltrust.com (red)... 550 Host unknown
>554 <ngw_at_lists.teltrust.com>... 550 Host unknown (Valid name but no A or MX)
However, sometimes messages to the same recipient
are delivered.
I have the suspicion that this version of sendmail
(possibly tweaked by DEC) may handle a failed looked
differently than other machines we have running the
same version of sendmail. Our bastion host is very
overloaded and may not be able to resolve the A ro MX
records for the destination address in time. However,
I would expect that sendmail would queue the message
in this case inicating a failed lookup.
Any ideas are welcome.
Ryan Day
Received on Fri Mar 14 1997 - 11:35:50 NZDT