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ari24

asked on

host name lookup failure

The following issue is going on for about 2 weeks now:

When AOL users send an email to my domain -brgny.com-, the messages are delayed many hours and are often returned as undeliverable: "Deferred: Name server: brgny.com.: host name lookup failure".

We receive thousands of messages a day and as far as I can tell, this is only happening with AOL users. One interesting thing is that mail sent to a "backup" domain name, that all email addresses have by default, are delivered immediately.

Messages we send to AOL are also delayed for many hours, and we are using a smart host for outbound email.

We do use greylisting as a spam prevention tool, but the messages are not showing up in the greylisting log, and emails to the "backup" domain are delivered quickly and without incident.
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nifiction
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You should deactivate greylisting as a test. If that does the job, at least you know that the way you apply it is not correct. It is actually not as straightforward as it should be, sometimes.

Also do a blakclist lookup from the IP which has the problems. www.dnsbl.info is one of the better and comprehensive search tools. Make sure you do the advanced search...

If all that does not give you new insights, you might consider using a commercial spamfilter (e.g. www.spamexperts.com). Big advantage of the solution is that it functions as a gateway and thus, all connections will be coming from a trusted host. Furthermore, the databases used are updated and maintained in real-time and spam-traffic thus has no chance to come through.
Avatar of ari24
ari24

ASKER

We are using a commercial spamfilter installed locally, which is what does the greylisting. As I said, the AOL messages are not listed in the servers spam logs.

The server ip is not listed in any blacklists.
ari24,

can you access the raw logs from all filtering activities (not only greylisting) performed? Which filter are you guys using?
Avatar of ari24

ASKER

We use Vamsoft Open Relay Filer and I have access to all logs.
I dont think my server is bouncing these messages.
If it were, the bounces would contain different messages and the alternate domain name would fail just as the primary often domain does.
For undelivered messages, no record of any transaction between my server and AOL appear in my spam filter logs, nor in the exchange smtp recieve logs.
Avatar of ari24

ASKER

Now the backup domain name is exhibiting the same problem.

Thru google, I am seeing similar issues now being reported by other users who host their DNS at enom, like I do. http://groups.google.com/group/hosted-the-basics/browse_thread/thread/3cc5ae6ed875729e/50fad0e5c14e5581?lnk=raot

I've opened a trouble ticket with enom.
ASKER CERTIFIED SOLUTION
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s_sykes
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Avatar of ari24

ASKER

I've set up an alternative DNS, but when i go to enom to change from their DNS servers to the new ones, it gives me the following warning:

If you switch away from our name servers, your domain name will no longer work with our provided services...
Any change in DNS Servers performed in this section will take approximately 24 hours to propogate
Do you wish to continue?

Will my web site and email be unreachable while the change propogates for 24 hours??
Servers cache DNS info, so they may reference the wrong DNS server until they update their information.  This can take 24 hrs or more, but usually happens much faster in my experience.  Your site and email should still be reacheable, but some servers may still query for the IP address of your mail or webserver at the old DNS host (eNom), but it shouldn't really matter as long as the IP of your mail server and webserver are not changing.  The only problem with the old DNS will be with AOL who will probably be slowww to update their DNS cache if I had to guess.

Also, you can't use eNom's webhosting or email services if you are not using their DNS as far as I understand.  I believe that is what the first part of the warning above is talking about.  I have domains through eNom both using and not using their DNS with no problem, but I don't use any of their other services, so it's never been a problem for me.  It's a shame, their DNS has been super reliable up till now, but then again, it's probably AOL's fault!
Avatar of ari24

ASKER

Got this response from enom:

Thank you for contacting Technical Support regarding this issue. In regards to the issue with AOL email failure. This is a known issue we are working on directly with AOL and expect this to be resolved shortly.

Please let me know if you have any additional questions regarding this matter. Thank you for your continued partnership, we appreciate you working with us.
Avatar of ari24

ASKER

I left my DNS with enom, and mail flow to & from AOL, AIM, and CS all seem to have begun working once again.