Reverse DNS Update

Just made the switch from Verizon DSL to Comcast Hig Speed.  Everything went without a hitch, only thing we still need to do is setup the Reverse DNS for our new IP Address.  I spoke with the tech who set us up and he directed me to the forums for the quickest response.

Our Comcast Acct Number is ________________

Our new Static IP is xx.xx.xx.237

And the reverse dns needs to point to "mail.leadershiparlington.org"

Can someone here get this taken care of for us?

Thanks!