Domain Names/Static IP
Managing, controlling, and support for Custom Domain Names
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Reverse DNS No Longer Works

We are now seeing multiple errors from our Exchange server that mail is bouncing back with the error message -

 

            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.

            <mail.ABELWOMACK.COM #5.5.0 smtp;550-Your server IP address [23.25.209.84] does not have a valid reverse DNS>

 

We have already contacted support by phone and are still waiting for a call back.  The messages on the boards seem to indicate that the mods are they ones who need to make the fixes to reverse dns . If that is the case could some please update reverse dns for the following records

 

 

23.25.209.84  exch15ma.abelwomack.com

23.25.209.84  mail.abelwomack.com

23.25.209.84  mail2.abelwomack.com

 

As fara as I know, this was setup previously and working for the last 12+ months.

 

ANy questions please let me know.

 

Thank you,

 

Tony D'Arezzo

IT Manager

Abel Womack

www.abelwomack.com

 

 

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Re: Reverse DNS No Longer Works

From my perspective it looks like some of Comcast's DNS servers are reporting a generic comcast reverse lookup (23-25-209-84-static.hfc.comcastbusiness.net) while others are returning the PTR records you want...   the ones that are returning bad info seem to have an old SOA serial from a month ago and the good ones have one that appears to reflect that the zone was updated today.    Because there are conflicting responses from the different DNS servers, some resolvers are going to cache bad answers for a while - once all of the servers are reporting current consistent information, and given some amount of time for the incorrect caches to expire (perhaps an hour or so), then your reverse lookups should match your exchange servers greetings.

 

Of course, if the Comcast DNS servers are reporting inconsistant reverse lookups suddenly, I imagine they have something that needs to be investigated anyway just to prevent others from also having problems.

 

Edit: As I've been typing, it looks like the updates are propagating across Comcast's DNS servers.. it may be that your request already got some attention.  In any case, I think the mods here simply notify the same groups that the phone support reps do, but the forum mods seem to have a better understanding of DNS.

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New Contributor

Re: Reverse DNS No Longer Works

From my perspective it looks like some of Comcast's DNS servers are reporting a generic comcast reverse lookup (23-25-209-84-static.hfc.comcastbusiness.net) while others are returning the PTR records you want...   the ones that are returning bad info seem to have an old SOA serial from a month ago and the good ones have one that appears to reflect that the zone was updated today.    Because there are conflicting responses from the different DNS servers, some resolvers are going to cache bad answers for a while - once all of the servers are reporting current consistent information, and given some amount of time for the incorrect caches to expire (perhaps an hour or so), then your reverse lookups should match your exchange servers greetings.

 

Of course, if the Comcast DNS servers are reporting inconsistant reverse lookups suddenly, I imagine they have something that needs to be investigated anyway just to prevent others from also having problems.

 

Edit: As I've been typing, it looks like the updates are propagating across Comcast's DNS servers.. it may be that your request already got some attention.  In any case, I think the mods here simply notify the same groups that the phone support reps do, but the forum mods seem to have a better understanding of DNS.

View solution in original post

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Re: Reverse DNS No Longer Works

Thank you for the update.  As you can imagine when emails fail everyone come screaming to IT. I was trying every channel to resolve this as quickly as possible.  For example we still have not heard back from our phone support request.

 

 

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Re: Reverse DNS No Longer Works

I'm just another customer who happens to know my way around the DNS.   My resolvers are getting correct PTR records now so hopefully picky mail servers will be a little more accepting of your messages and reduce your IT workload.

 

As far as the forums go, it seems like it's a good place to go in order to get things done right when the phone support fails us, but it's not a quick process.  Ah well.. I finally got my issues resolved so now I try to see if I can help out fellow customers when I have a spare moment.

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