Solved

Comcast and Others refusing emails (No PTR Record?)

Posted on 2013-02-04
6
1,859 Views
Last Modified: 2013-02-10
I recently installed Exchange 2007 SP1 on A server 2008 64bit Server.  I also installed a Barracuda Spam Firewall 200 on the DMz.  All Mail seems to be flowing fine with the exception of a few mail servers refusing our email (shown in the Barracuda Outbound queue as deferred).  We use Bluehost as our Zone records holder.   I have created all the A records as instructed by bluehost.

The mail servers refusing our email seem to be Comcast, AOL, Cox.net, Juno, and a couple others.  I contacted Bluehost who stated that it looked like it was a Barracuda issue.  So I bypassed the Barracuda for Outbound mail. Still refused by server.  I contacted Comcast who confirmed that they could not verify by rDNS.

I then Contacted Bluehost again to add a PTR record.  They claim that the PTR has to be setup on our internal DNS server.  

I am not sure where to turn to now.  I added a PTR record to our Reverse zone look up, but not sure if I did it correctly.

Can anyone tell me how to set up the PTR Record in our internal DNS to resolve the rDNS issue?

Does this look like it may resolve the issue with the PTR record?

Do I add a PTR Record for the Barracuda External IP on our internal Domain?

HELP!!!  It seems like all the members of our Board of Directors use Comcast, and our executive Director is about to have my Head on a Platter.
0
Comment
Question by:HOF_Admin
6 Comments
 
LVL 7

Accepted Solution

by:
Robby Swartenbroekx earned 500 total points
ID: 38854047
PTR record has to be setup with your internet provider. your ip, you received from them, must resolve to your mail server.
0
 
LVL 10

Expert Comment

by:Damjan
ID: 38854083
Yes, your ISP  MUST set up the reverse DNS for your IP on their end.
http://mxtoolbox.com/diagnostic.aspx - here you have great mail server diagnostics tool, where test and verify the server has a reverse DNS (PTR) record too.
0
 
LVL 6

Expert Comment

by:Kailash Aghera
ID: 38854113
Only your ISP (internet service provider) can set rdNS for your IP address. If this is the new IP address, I also suggest you to check the blacklisting as well to avoid the problem in future. You can check it from the following URL:

http://www.mxtoolbox.com/blacklists.aspx
0
Ransomware: The New Cyber Threat & How to Stop It

This infographic explains ransomware, type of malware that blocks access to your files or your systems and holds them hostage until a ransom is paid. It also examines the different types of ransomware and explains what you can do to thwart this sinister online threat.  

 

Author Comment

by:HOF_Admin
ID: 38855662
Thank You for all your replies,
Blacklist are clear.
Our DNS Zone records are managed by Bluehost, but AT&T is our ISP.  I just sent a request to AT&T since Bluehost says everything is good on their side.   We will see if AT&T can help.

Thanks Again!
0
 
LVL 6

Expert Comment

by:Kailash Aghera
ID: 38857238
Once your ISP sets rDNS, you will have to allow few hours for the propagation of rDNS.
0
 

Author Comment

by:HOF_Admin
ID: 38874439
Ok, so now bluehost claims that they do not add custom pointer records at this time.  So i will be transferring our DNS to AT&T.  Once i Get this accomplished i will divvy out the points for the solution....
I find it really hard to believe that there are no other Blue Host clients that have exchange in-house.

Update:
All is well after moving our DNS hosting to AT&T.  I have added the pointer and even before updating the name servers for our website on Bluehost, Comcast and several others that were previously refusing our email began accepting.  AOL took an extra day even though I used the AOL Postmaster tool and was able to verify that rDNS was working.

It was really helpful to have Experts-Exchange members assistance to confirm the correct solution while attempting to have a third party make the changes necessary.
0

Featured Post

Visualize your virtual and backup environments

Create well-organized and polished visualizations of your virtual and backup environments when planning VMware vSphere, Microsoft Hyper-V or Veeam deployments. It helps you to gain better visibility and valuable business insights.

Question has a verified solution.

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

Scam emails are a huge burden for many businesses. Spotting one is not always easy. Follow our tips to identify if an email you receive is a scam.
Find out what you should include to make the best professional email signature for your organization.
how to add IIS SMTP to handle application/Scanner relays into office 365.
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

685 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