Mailing List Message #10124
From: Brian Findlay <>
Subject: resolving domains, with multiple domains on server?
Date: Thu, 31 Jan 2002 09:22:33 -0800
To: <sims>
X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0)

I have been having some problems, related to our local ISP in town bouncing messages, and not delivering them, due to the 'from' domain (my server)'not resolving'.  This confuses me.  My DNS records with Network Solutions, are set up correctly, and the domains themselves serve just fine.  Performing a whois on any of these domains correctly points to my (single IP) server.  The general settings main domian in SIMS is set to another domain (not mine), and if I switch it, the routre doesn't recognize any addresses anymore.

Here is a snip from the sysop at the ISP, telling me what the problem is...

**** bounced message clip ****

... while talking to
>>> MAIL From:<> SIZE=565
<<< 451 4.1.8 <>... Domain of sender address does not resolve
<>... Deferred: 451 4.1.8 <>... Domain of sender address does not resolve
Warning: message still undelivered after 4 hours
Will keep trying until message is 3 days old

****** end *****

***** ISP sysop reply to my inquiry *****

Here is what I get when I look you up: (more below)
"sun:/work/users/akoppel# nslookup

Non-authoritative answer:


*** can't find Non-existent host/domain

That means that I can translate to an address

when mail comes from, I do not know who the heck you are,
so I do not trust you, so I will not handle your mail.

Talk to the name of the person who handles your DNS resolution.. and have
him check/update his REVERSE DNS table (  as well as table.ptr).

If you share this message with you provider, he should know what I mean.

This is independent of your Whois entries.

*****  end   *****

So what does all this mean??  What is a 'REVERSE DNS' table, and where is it, and how do I update it??  I manage the DNS server for this site (MacDNS), and I looked for such a setting, but could see nothing that seemed close.

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