Re: [NTISP] Weird SMTP problems

Kevin ( (no email) )
Fri, 22 Oct 1999 22:18:57 -0400

Does this affect all your domains to these domains or just some?

Are you sure that your upstream provider completed the reverse delegation
of the address set to your DNS servers? If they didn't then your entries
into the
in-addr will not be recongnized.


----- Original Message -----
From: Malcolm Joosse <>
To: NTISP <>
Sent: Friday, October 22, 1999 9:27 PM
Subject: [NTISP] Weird SMTP problems

> Hello List,
> I have recently changed backbone providers and have noticed a few email
> problems.
> We run NT only with NTMail 3.02M and Pri/Sec DNS servers local.
> I am having trouble with about 5 email domains that cannot seem to send or
> recieve to my clients mailservers on my network. They can send/recieve
> from many other domains like, and others, so I cannot
> beleive there is a DNS problem
> I have watched the SMTP log and noticed that when their server connects
> seems ok,
> we connect then I see an error 521 does not resolve. I
> donot know why it is trying to resolve our customers domain and not the
> mailserver domain name
> I have also noticed that we connect to their server but then I get
> closed the connection.
> I can't tell where the problem lies, but I have completed the reverse DNS
> registration about 5 days ago, but I do not think this is the cause.
> Please help
> Regards
> Malcolm Joosse
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