How to find your domains MX record - NSLOOKUP

If you recently added a new domain to your mail server you may need to wait for DNS to propagate the MX records, which could take up to 72 hours, here's a couple of tools you can use to lookup the MX records to see if it did propagate.

• NSLOOKUP (DOS command)
• IP Tools (Online utility)

NSLOOKUP. Open a DOS prompt and type 'nslookup', without the single quotes, it should show what DNS server it's using (usually the default for your Ethernet adapter) and the DNS server IP. Type 'help' for a list of all commands. Then type 'set q=mx'. This tells nslookup to lookup the MX records for the domain entered at the nslookup prompt. For example, type your_domain.com and the MX records will be returned, if the domain has MX records. For example, type google.com and you will see results similar to the following,

Non-authoritative answer:
google.com MX preference = 10, mail exchanger = smtp2.google.com
google.com MX preference = 10, mail exchanger = smtp3.google.com
google.com MX preference = 10, mail exchanger = smtp4.google.com
google.com MX preference = 10, mail exchanger = smtp1.google.com

smtp2.google.com internet address = 64.233.165.25
smtp3.google.com internet address = 64.233.183.25
smtp4.google.com internet address = 72.14.221.25
smtp1.google.com internet address = 209.85.237.25
>

The results show that google.com has 4 MX records, all set to preference 10 (kind of like a round robin approach), and then it list the IP's for each MX hostname.

Another way to use nslookup is to change the DNS server it uses to see if other DNS servers report different results than your default DNS server configured on your Ethernet adapter (TCP/IP settings). After entering the nslookup prompt type 'server new_dns_server_IP', where new_dns_server_IP is the DNS server IP or hostname you want to use to check records against, it could be a secondary DNS server on your local network or your ISP's DNS server. Then perform the lookup on your domain to see what that DNS server reports.

IP Tools. IP tools, located at www.iptools.com, is a great tool for checking more than just MX records, you can check rDNS, IP's, A records, etc... what's handy about IP Tools is that you get a "second opinion" on DNS records or MX records for a particular domain, just in case your concerned about your DNS cache or TTL on your DNS servers.