"Reverse DNS" provides the ability to lookup an IP address and find out which domain name it is associated with. This is useful because many SMTP servers do a reverse DNS check before accepting mail in order to prevent SPAM.
The only party that truly has access to provide you with reverse DNS on your IP block is your ISP. Your ISP has the power to either delegate authority for reverse DNS to another party, or to provide reverse DNS themselves.
We can't simply setup reverse DNS for you unless you have a colocated or dedicated server with us. If you need reverse DNS for your home or office broadband connection, please contact your ISP.
At this point, we don't provide free reverse DNS, so your best bet is to ask your ISP to provide it to you directly rather than having it delegated to us.
We do, however, provide specialized reverse DNS on the enterprise level if you are in need of this service.