Let me give you a little look at my scenario:

1 - Dedicated Server hosted by EV1
2 - Exchange mail server hosted on location at my site
3 - Public IP's for exchange and mail owned by ATT

I have the mail and mx records setup in my plesk dns for the domain. and all mail is routed over to my exchange server. However when I or AOL try to run a reverse lookup on my mailservers IP it fails because it does not return mail.mydomain.com

i have add the ptr record for my domain xx.xxx.xxx.70 /24 (that is all plesk allows) in the dns configuration on my domain. and i am still not getting an answer back on the reverse dns query.

Any help is greatly appreciated.

you can not create the ptr for the ip since you do not own the block. ATT would have to create the ptr for you in which i doubt would happen unless you have a business SLA

Thanks for the reply. I have a business SLA with ATT but they told me that they can't or won't anyway update any PTR records unless I use them as the primary DNS for my domain.

Does ATT will charge you for using their DNS service? If the anwser is no... set up your domain record with ATT exactly as in the plesk box ( except for the NS records ) and point your domain to the two DNS from ATT and add a third one ( your plesk box )
Then change the NS records on the plesk box to match the whole setting ( two ns records from ATT and a third one... your plesk box )
That will make happy ATT and get your reverse DNS working

P.D. You will also have to add a third NS record on the ATT DNS pointing to your plesk box

strange.. maybe you can outsource your email