Ive been on this for about a month. I have control over my own static ip thru comcast business, ipv6 however is a little a different on how they hand out ipv6 addressee and how your devices use them statically, after i got all that out of the way. i fail to find how you edit or amend zone forwarding and reverse records in mail in a box . no file is really editable globally and if mail in a box is a dns host and i cannot manually insert the ptr record from bind from this site
http://rdns6.com/hostRecord
i am running ubuntu on vmware 6.5 and mail in box sees the public ipv6 address and comcast delegates my ipv4, why cant i put in the zone file and record for ipv6 ptr so my mail doesnt get bounced back. Thank you
Because PTR records need to be set by the owner of the IP, i.e. Comcast. You’ll need to contact them to set it if they do not provide you any interface to do so with.
comcast only handles the ptr for the ipv4, on ipv6 they hand you a block of addresses, ive called them repeatably. so i would have to host those records on another dns server?as another name server?
how would you do it in a private network?
I’m going to try and explain how reverse DNS works.
There are two parent zones in-addr.arpa. ar any nd ip6.arpa.
When Comcast or any other ISP is given a block of IP addresses the DNS nameservers for those zones are given to them.
However they don’t just have to add PTR records to those zones. If they give a block of IP’s to a customer, and typically these will fall on a byte boundary there is nothing stopping the ISP from adding NS records to the parent zone in the same way that your registrar adds NS records to the parent zone for forward DNS.
When I had a HE.net tunnel they allowed you to delegate the nameservers for your /64 and /48 to the nameservers of your choice.
That said Comcast does not appear to support delegation or the addition of the records to the parent reverse zone, either PTR or NS records 
Are you on a residential plan and allowed to run servers on it?
The folks in charge of IP allocation go give guidance that ISPs are supposed to delegate down reverse lookups (see below) but plenty of ISPs do not do so presumably with the reasoning that there shouldn’t be a need if servers are not allowed.