Creating a reverse DNS record may only partially resolve your problem.
Without looking at it, the problem could be a number of things.
The obvious answer is to add the appropriate PTR record, however -
Do you have a static IP address that your ISP has assigned you (have they assigned static reverse records for your address space if yes?)?
Do you have the correct certs installed?
Do you have your hostname configured properly?
Edit: Corrected Spelling xD