Re: proper dns listings for mail servers

Thanks Andy. But if the mail server has an internal IP address, what
do you specify on the external DNS? Do you assign a new external IP
ie. 200.xxx.xxx.x for the address? Or do you point it to the firewall
IP address? If that's the case, it will create problems for folks
using the VPN service that's built in on our firewall.


Andy David - Exchange MVP wrote:
> On Tue, 9 Aug 2005 17:36:36 -0700, "Shannon Hemmes"
> <shannonela@xxxxxxxxxxx> wrote:
>
> >hi there,
> >
> >It's come to my attention recently that some sites are using rdns lookups
> >and in some cases rejecting mail from our domain. I've inherited managing
> >these systems & so am just learning the current setup.
> >
> >I figure we have something misconfigured in our external dns (hosted by an
> >ISP). I'd like to know what the proper DNS configuration should be.
> >
> >Our setup:
> >
> >Firewall: firewall.domain.com (200.xxx.xxx.x)
> >Spam filter: spam.domain.com (10.x.xx.x)
> >Internal mail server (exch2k3): mail.domain.com (10.x.xx.x)
> >
> >Mail being sent out from our domain is routed thru the firewall:
> >mail.domain.com>firewall.domain.com
> >Incoming mail takes the following route: firewall>spam filter>internal mail
> >
> >Our ISP DNS has ptr record for our domain, that points to the firewall IP.
> >They also have an mx record that points to our firewall.
> >
> >In looking at the message header from a message sent from our domain, shows
> >the following received from path:
> >Received: from mail.domain.com (firewall.domain.com [200.xxx.xxx.x])
> >
> >My guess is that we should have either an mx or a ptr record called
> >mail.domain.com that points to the firewall IP? Would this be correct?
> >Anyone care to do some explainin' to me?
> >
> >Thanks very much,
> >
> >Shannon
> >
>
> You need a ptr record for the ip address of the host that is sending
> the mail.
> Check your domain at www.dnsreport.com

.

Relevant Pages

  • Re: proper dns listings for mail servers
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