Solved

Reverse DNS PTR record

Posted on 2007-11-28
9
2,822 Views
Last Modified: 2012-06-21
I have a client that is having emails to AOL email addresses bounce.  I have read about why this may happen with AOL and it seems to be related to them not accepting email from domains that do not have PTR or SPF records setup for a reverse DNS zone.  I called the ISP of my client and had them setup a PTR record and it has propagated.  I sent a test email from that domain to an AOL account and it has been about a half hour and the email has not been delivered nor has it bounced.  If I went to setup the SPF record do you think that would fix the issue.  It appears that this only happens with AOL accounts.
0
Comment
Question by:pcmb
  • 2
  • 2
  • 2
  • +3
9 Comments
 
LVL 21

Expert Comment

by:from_exp
ID: 20368742
does your ISP have correct TTL set for that IP address.
some antispam companies like sorbs asks for valid PTR AND TTL set to be greater than 43200
0
 
LVL 16

Expert Comment

by:2PiFL
ID: 20368880

I had to add a SPF record to get mail to AOL.  If you need help here is a good Wizard:
http://www.openspf.org/wizard.html 
0
 
LVL 1

Author Comment

by:pcmb
ID: 20368981
The TTL is set to 86400.  However, the PTR record resolves to the public IP of the domain in question but it gives an error because the A record is resolving elsewhere because they subscribe to an MX spam filtering service.
0
PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

 
LVL 10

Expert Comment

by:brakk0
ID: 20368982
I had the same problem with PTR records and AOL, but I don't think they require SPF records (since so many sites are not using them yet).

I would say just wait a day or so and try it again. It may take more than a half hour for their cache to clear out.
0
 
LVL 21

Expert Comment

by:from_exp
ID: 20369490
I would agree with brakk0, to wait for a day.
Normally 24 hours are enough for dns to renew all cache entries
0
 
LVL 31

Expert Comment

by:moorhouselondon
ID: 20377280
Just to confirm brakk0's comment.  SPF is definitely not mandatory to successfully send emails to AOL.  However, if AOL operate a scoring system for assessing acceptability, then it would surely help to have SPF.  Plus in the future the goalposts will move.
0
 

Accepted Solution

by:
jwr51 earned 250 total points
ID: 20438482
For those who need a quick fix, AOL and Craigslist will accept Exchange emaill without a valid reverse DNS record if you route your Outbound mail through a valid email account with a recognized ISP. Read this link - http://www.amset.info/exchange/smtp-connector.asp.
I use my account at sbcglobal.net which has an Outbound mail server at smtp.att.yahoo.com.
You need to set your email login details on the SMTP Connector/Advanced/Security page.
I am still trying to get a valid reverse DNS pointer from AT&T but I have heard that this may not help if you have a DSL connection.
0
 

Expert Comment

by:jwr51
ID: 22805736
The Reverse PTR Red Herring.
I added SPF records to my GoDaddy DNS records and have successfully sent mail to AOL, and Hotmail from a private Exchange Server. Before I added the SPF records, mail to AOL and Hotmail was being returned as undeliverable. See attached file for my GoDaddy DNS records.
GoDaddy-MX-SPF.pdf
0
 
LVL 31

Expert Comment

by:moorhouselondon
ID: 22806429
It did not used to be mandatory, the Goal Posts must therefore have moved.  See my comment about "scoring" above.  The "weighting" of Reverse PTR in that scoring "mix" will however - currently, at least IMO, be "heavier" than SPF, purely because adoption of SPF currently is much lower.
0

Featured Post

How Do You Stack Up Against Your Peers?

With today’s modern enterprise so dependent on digital infrastructures, the impact of major incidents has increased dramatically. Grab the report now to gain insight into how your organization ranks against your peers and learn best-in-class strategies to resolve incidents.

Question has a verified solution.

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

We are happy to announce a brand new addition to our line of acclaimed email signature management products – CodeTwo Email Signatures for Office 365.
This article explains how to install and use the NTBackup utility that comes with Windows Server.
In this video we show how to create an email address policy in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Mail Flow…
This video demonstrates how to sync Microsoft Exchange Public Folders with smartphones using CodeTwo Exchange Sync and Exchange ActiveSync. To learn more about CodeTwo Exchange Sync and download the free trial, go to: http://www.codetwo.com/excha…

820 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