Multiple Domain Reverse DNS 1

[gbaughma]

I host a couple of domains. I have a SonicWall and an Exchange 2007 server.

Meanwhile, we're running into some delivery delays, because when we deliver to some hosts, it does a reverse lookup, which isn't matching.

In other words, if I send an email from "DomainB", the receiving system is doing a reverse looking on "DomainB" and getting an answer of "DomainA". It then delays delivering the email for 24 hours. This is, needless to say, causing some issues.

I have several external IPs that I can use, so it's not a problem to change them around so that DomainA and DomainB have their own IP addresses, however I have one exchange server hosting both domains.

Since the Exchange server is going to send email out of the "Primary IP" on the SonicWall, I don't think that changing around the DNS is going to resolve my issue, since DomainB would still be sending out of DomainA's IP address, so reverse lookup isn't going to work properly (I think).

Anyway, does anyone have any solution for this for me? Since we send mail from both DomainA and DomainB, I need reverse lookups to work properly for both.

Thanks in advance!


Just my 2¢

"What the captain doesn't realize is that we've secretly replaced his Dilithium Crystals with new Folger's Crystals."

--Greg

http://parallel.tzo.com

 

[ShackDaddy]

It's much much simpler than you think. You know, down deep in the Default SMTP Virtual Server, under the Delivery -> Advanced tab where it gives you the chance to put your FQDN? Just make that match what you've provided for your RDNS record. When you send outbound mail, your server gives it's name to the receiving server, and THAT'S what's checked against the RDNS record. It doesn't matter what domain name your users are using when they send outbound. It doesn't matter if you have 30 potential outbound domains. The RDNS check is just to verify that the IP your server is coming from is linked to the same name you are giving when you make the connection.

Just make sure that the same IP you get when you go to IPChicken.com from the mail server is the IP you create an RDNS record for.

Dave Shackelford MVP
ThirdTier.net
TrainSignal.com