Reverse IP Needed For Domain That's Not Externally Addressable?

  • Thread starter Thread starter Alex Davidson
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A

Alex Davidson

While communicating with the provider of our Email Content-Checking/Security
provider he mentioned that our mail server failed a Reverse DNS Lookup and
that from next week our messages would start bouncing. He also mentioned
that other companies are starting to do the same thing which I can
understand.

I am now very concerned about how we have set up our Active Directory DNS
Server as we went with a non-addressable name of SMI rather than the domain
name that we use for email. The logic was that:
1. It doesn't really matter what it is as it's for internal use only
2. If we have the same domain name as our email addresses it could only
cause confusion to the internal DNS system

Anyway, the headers of an email sent externally report (with IP changed to
protect the innocent):
Received: from aragorn.smi [123.456.789.012]
so I guess if we want it to pass a Reverse DNS Lookup it's need to say:
Received: from aragorn.domain.com [123.456.789.012]
and have a DNS entry in the publicly-addressable world pointing
aragorn.domain.com to 123.456.789.012.

The (only) good news here is that we host our domain with dyndns.org so I
can add/change entries on a whim but it doesn't really help me as I have no
idea how to implement a change on the mail relay server from SMI to
EMAILDOMAIN.COM

Can anyone offer any advice on how we can achieve this change?

Thanks,
Alex
 
Well my email content-checking guy was nice enough to give me a quick fix:
go into IIS and ensure that the fully qualified domain name shows as
mail.domain.com

Sorry for the (as it turns out) unnecessary post. If nothing else hopefully
it could answer the same question for another person in my position.

Alex
 
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