LeapFish.com Domain Name Resource Center
DNSCog - DNS reporting and diagnostic tools
Fast Domain Name Search | Domize
intoDNS: checks DNS and mail servers health
SPF Wizard - SPF Generator DNS tool
DNS Checker - Worldwide DNS Propagation Checker
DNSdumpster.com - dns recon and research, find and lookup dns records
DNS Lookup - MxToolbox
Use Our Domain Name Tool to Analyze Your Web Address | Network Solutions