We help IT Professionals succeed at work.

We've partnered with Certified Experts, Carl Webster and Richard Faulkner, to bring you two Citrix podcasts. Learn about 2020 trends and get answers to your biggest Citrix questions!Listen Now

x

rDNS problem

PatGroupIT
PatGroupIT asked
on
Medium Priority
333 Views
Last Modified: 2010-03-06
Quick rundown:  we recently migrated exchange and DNS servers, I don't think this has much to do with the problem.  Our domain's MX records point to a 3rd parties IP that filters spam for us then forwards cleared messages to one of our public IPs.  Our outbound SMTP traffic goes out of the same public IP the 3rd party forwards to, but there is obviously no MX record.  

Now we are starting to get blacklist/HELO bounce back errors from a few domains.  This has everything to do with our outbound SMTP and MX records being different, no?  Do we pretty much have to unify the IPs or is there some work-around?
Comment
Watch Question

CERTIFIED EXPERT

Commented:
Hi PatGroupIT,

Have you got a PTR record for you IP address?

What is you domain so we can have a look and test it out?

-red

Author

Commented:
Yep, we have a PTR record set up on our internal DNS server,  but it doesn't have an external address or NAT or anything.  The domain is patinagroup.com
CERTIFIED EXPERT

Commented:
Your internal DNS server?

What is your external IP address?

Your domain looks fine so far...

-red

Author

Commented:
Yep, DNS server with a private address and no public.  External for smtp outbound is 64.161.229.131...different than the MX record.
CERTIFIED EXPERT
Commented:
This could be the problem,

There is a reverse DNS entry for that IP, but that does not have a corresponding A record

http://www.dnsstuff.com/tools/ptr.ch?ip=64.161.229.131

Get your ISP to create an entry that matches the PTR record

-red

Not the solution you were looking for? Getting a personalized solution is easy.

Ask the Experts
CERTIFIED EXPERT

Commented:
... or change the PTR record to match your servers real name (that it has an A record for)

Author

Commented:
Might this new A record conflict with the DNS entry for the website (hosted at yet a 3rd outside IP)?
CERTIFIED EXPERT

Commented:
>Might this new A record conflict with the DNS entry for the website

It shouldn't, but your DNS looks to be of an "interesting" configuration.

Ask the ISP and see if they can create an A record that matches the reverse lookup - that will not affect the website in any way at all

-red

Commented:
Check if your ISP collecting email on your behalf has PTR record configured for your email domain.
Access more of Experts Exchange with a free account
Thanks for using Experts Exchange.

Create a free account to continue.

Limited access with a free account allows you to:

  • View three pieces of content (articles, solutions, posts, and videos)
  • Ask the experts questions (counted toward content limit)
  • Customize your dashboard and profile

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.