We have a situation where we administer our own email
(reddotbuildings.com) which resolves to our secondary ip, but our
is administered by a third party, which resolves to our primary ip,
has an "A" record tied to the third party's ip. The problem is, those

email systems that use reverse DNS lookups on incoming email will not

accept our incoming email since no "A" record exists which is tied
back to
our secondary ip, which is where the email originates from.

I tried having our isp add an entry in their DNS servers which would
back to the secondary ip, which they were glad to do, but this setup
does not apparently satisfy our desired recipent's reverse DNS lookup.

Any ideas?