I was a bit hasty in assuming that the problem was resolved.  The error
still occurs whenever DNS lookup cannot be done on an address.  The
sendmail job is aborted and placed in the Listserv spool directory (as a
file with name similar to 1234.mail).  The job usually contains approx 100
addresses and none of these receive the posting because one domain is
unreachable.  I have been manually deleting the line containg the invalid
address and restarting Listserv which requeues the file(s) for delivery and
sends them out (providing there are no other similat DNS problems).  This
is a big pain and for large lists this happens quite often.  Has anyone
encountered this problem and/or have a solution??

Gary Bannister
NetAccess Systems Inc.

On Sat, 22 Sep 2001 07:41:54 -0400, Gary Bannister <[log in to unmask]> wrote:

>Thanks Valdis!
>I added the 'FEATURE(nocanonify)' to my sendmail.mc and although I still
>see the errors in my log file (which makes sense) it no longer prevents the
>message from being delivered to the other recipients.
>
>Gary Bannister
>NetAccess Systems Inc.
>
>
>On Wed, 19 Sep 2001 15:39:53 -0400, Valdis Kletnieks
><[log in to unmask]> wrote:
>
>>On Tue, 18 Sep 2001 22:32:55 EDT, Gary Bannister <[log in to unmask]>  said:
>>> We have recently upgraded to the above environment.  The problem is that
>when sending out mail if Listserv comes across a subscriber's domain that
>cannot be found (e.g., DNS servers are not reachable) then the error
>messages below are produced and no messages are sent out.  There is a file
>(e.g., 12345.mail) that sits in the spool directory indefinitely because of
>the error.
>>>
>>> Has anyone come across this problem?  It appears that some configuration
>change is need for Sendmail to let it ignore this error and continue
>processing the list of addresses.
>>>
>>> -> RCPT TO:<[log in to unmask]>
>>> 450 4.7.1 <[log in to unmask]>... Can not check MX records for
>recipient host S
>>> ITCOM.NET
>>> 17 Sep 2001 01:35:27 >>> Error X'00C00E13' enqueuing mail for delivery
><<<
>>> 17 Sep 2001 01:35:27  -> Severity: Error
>>> 17 Sep 2001 01:35:27  -> Facility: SMTP error code
>>> 17 Sep 2001 01:35:27  -> Abstract: Unspecified error (450) - See RFC821
>et seq
>>
>>DNS for sitcom.net is provided by ns1.best.com, ns2.best.com, and
>ns3.best.com,
>>which however don't realize they are supposed to be providing DNS for it.
>>The SOA for 'best.com' points you to [log in to unmask], who should be trying
>to
>>fix it.
>>
>>As far as a workaround goes, added 'FEATURE(nocanonify)' to your
>sendmail.mc
>>file, re-m4'ing a new .cf file, and restarting Sendmail should help you
out
>>a bit - this will bypass at least some of the DNS checks and maybe defer
>>the 450 bounce until later (at actual delivery time).  It will also help
>>speed up the initial submission considerably (I measured a 6X speedup in
>>the handling of large lists when I originally did it many moons ago).
>>
>>
>>--
>>                                Valdis Kletnieks
>>                                Operating Systems Analyst
>>                                Virginia Tech