Name Server configuration checking tool
I manage couple of name servers and several domains. I am using BIND as a name server of choice, found it excellent, easy to configure and maintain, and most importantly, easy to secure (chroot).
A DNS Report is a very useful tool validation the configuration of your domains. To perform a test, you just need to provide a name of the domain. The tool performs a series of tests grouped into several categories including parent zone tests, name server config test, SOA record tests, MX record(s) test, Mail tests and www (web) tests. It provides you with an excellent report, with lots of comments, explaing every element of the tests, and providing lots of useful information how to fix any configuration problems dtected.
A must for any systems admin responsible for manageing name servers.
If you need more test, check out this web-site DNS Stuff to get even more information related to DNS. You get whois lookup service, you can check whether you server is recorded in one of the spam databases, ect. Very useful.