Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
?
Solved

reverse DNS question

Posted on 2008-10-21
2
Medium Priority
?
268 Views
Last Modified: 2010-04-07
I have installed a Barracuda spam firewall to filter all of my *outbound* email from my mail server.  Because of this, I now have a DNS question.

The public ip address of my email server is 12.34.56.1 and that is associoated with mail.mydomain.com

All outbound email goes from the mail server first to the Barracuda & then out to the internet.  When the Barracuda sends out the mail, the email is identified as coming from 12.34.56.2

Some email messages have been rejected because some recipient's servers attempt a reverse dns lookup on 12.34.56.2 & there is no reverse dns  lookup for that ip.
 
I'm guessing a solution would be to add a "reverse DNS" entry for 12.34.56.2 - mail.mydomain.com

However, I'm worried - I don't want any mail to be sent back to 12.34.56.2 since that is an outbound device only.  I want mail to only come in on 12.34.56.1

Is adding this reverse DNS entry safe?
0
Comment
Question by:brianp111
  • 2
2 Comments
 
LVL 2

Expert Comment

by:MobiNet-ca
ID: 22767215

I would create a reverse DNS record such as "outbound.mydomain.com" and point it at 12.34.56.1 and leave the records for the real mail server alone.
0
 
LVL 2

Accepted Solution

by:
MobiNet-ca earned 1500 total points
ID: 22767223
Sorry that should have been the .2 IP

I would create a reverse DNS record such as "outbound.mydomain.com" and point it at 12.34.56.2 and leave the records for the real mail server alone.
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

I wrote this article to explain some important DNS concepts that should be known to avoid some typical configuration errors I often see in forums. I assume that what is described here is the typical behavior of Microsoft DNS client. I don't know …
There have been a lot of times when we have seen the need to enter a large number of DNS entries in a forward lookup zone. The standard procedure would be to launch the DNS Manager console, create the Zone and start adding new hosts using the New…
When cloud platforms entered the scene, users and companies jumped on board to take advantage of the many benefits, like the ability to work and connect with company information from various locations. What many didn't foresee was the increased risk…
With just a little bit of  SQL and VBA, many doors open to cool things like synchronize a list box to display data relevant to other information on a form.  If you have never written code or looked at an SQL statement before, no problem! ...  give i…
Suggested Courses

572 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question