[TriLUG] What is the correct reverse dns set up for multiple domains on one server?

[Mark Fowle via TriLUG]

Can anyone enlighten me what the easiest way to do this is ?  Seems my
email from the hosts is bouncing and it appears my assigned IP from TWC
resolves to them as a dhcp IP.  Should I just remove all PTR records from
my zone files ?

Thanks,
Mark