RDNS/PTR is not working correctly. AOL vs MXTOOLBOX

The problem is that my RDNS records don't see to work on AOL (and a few other servers).

What can be causing my RDNS records to show up fine on the MXToolBox.com look up and fail the AOL RDNS lookup?

ptr:     ptr    
Type IP Address Domain Name TTL
PTR mail.pharmabioserv.com 60 min

DNS Server Response:

I have an open ticket on my ISP but they can't figure out why is this happening, any clue?
Who is Participating?
shauncroucherConnect With a Mentor Commented:
I can't speak for mxtoolbox but I can tell you that there is no rDNS for ,

neither is there any nameserver responsible for that IP or any others in the 237.80.208.in-addr.arpa. zone.

There is a nameserver for the 80.208.in-addr.arpa. zone though -  chia.arin.net (arin are the people responsible for allocating delegation for the in-addr.arpa. zones).

You need to speak with the supplier of your IP range to get this resolves, either they or you will need to setup a nameserver for the IP range.

Lost182Author Commented:
I have been working with my ISP to find out what is going on, and at this moment I need to understand that, they don't know what they are doing.

Now they have this theory where "the problem is that the mails are going out with a spoof IP".

There is any way I can show or prove that the problem comes from their site and explain how to fix this? Tools? Tests? Anything that can help me guide them on the right direction.
its very simple really, just point out that they havent set a ptr for the public ip address. if they call themselves an ISP they really should know this basic stuff. you should check the ip being used to send mail by loking at the header of a message you send outbound and check the ip in there belonging to you. this is the one that must have a valid ip. there are lots of reverse dns checking tools to pick from on internet to check the ip.

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