Question : Revers DNS hosting

I am hosting all of my dns. I had the ISP delegate all DNS to my server. I have a reverse lookup zone setup and a PTR for our mail server but for some reason it says it does not exist. I know it is hitting my DNS server looking for it. IP is 12.231.33.131 for my mail sever.

Answer : Revers DNS hosting

Are you able to resolve it internally.

Try using nslookup. If you dont get a reply then its been incorrectly setup.

Try recreating the pointer PTR record