Spampig DnsblCheck takes the IP address of a mail server and looks it up in common blacklists and whitelists. The program tests against the major block lists from Spamhaus, SORBS, Spamcop, Barracuda, UCEProtect, and others. In addition to blacklists, it also checks against IP address and domain name whitelists and even checks PTR record integrity. The program returns results quickly, typically in less than a few seconds. If you don't get results quickly, it indicates you may have DNS problems and knowing this can also be useful. This application can be useful to spam fighters and email users who are struggling to find out why their messages are being blocked.