Every now and again I like to run checks on my DNS servers to make sure they are running right and to RFC spec. I used to use the DNSTools website to do this as it gave me a pretty good picture of what was going on - are all my servers responding to the outside world, and the important (NS, MX especially ) records still up and replicated right. Also to see if my MX records have managed to make it onto any blacklists.
Blacklists have always been kind of a pain as I haven't been able to find a reliable "one stop shop" that lets you check against most of the major blacklists out there.
I haven't used DNS tools in a while and now they are requiring you to pay (which I have nothing against, just hard to justify to the superiors when you have invested in a large internal monitoring solution and I'm just doing a "feel good check")
What do my fellow sysadmins uses to check on their DNS records?