These instructions require access through SSH. Please see this article for assistance in connecting via SSH:
How To Connect With Putty Via SSH
General DNS Information:
dig yourdomain.com
MX Record lookup:
host –t mx yourdomain.com
dig mx yourdomain.com
SPF Record lookup:
host –t txt yourdomain.com
DNS tree:
dig +trace yourdomain.com
Registrar and Name Server lookup:
whois yourdomain.com
Test Server Connections on a Specific Port:
telnet yourdomain.com 21