Today I had to call my ISP(internet service providers), because they mucked up the DNS (Distinguished Name Service) of my mail server. I went to whois and reverse IP my mail servers external IP and got a different name. I was alerted to this problem because my mail was starting to get placed in SPAM traps.
After that sinking feeling of knowing that I had just lost my morning, I decided to make sure that nothing else was stepping on my DNS, could this just be a bad record in another DNS server? I asked myself.
So I opened up the "CMD" window from the run menu and typed in the DOS window:
> server DNS1.ISPNAME.NET
What this allowed my to do was lookup my IP's domain name in my ISP's name directory