Network Administration: Mail Server Location

If you’re having trouble delivering mail to someone, you can use nslookup to determine the IP address of the user’s mail server. Then, you can use the ping command to see whether you can contact the user’s mail server. If not, you can use the tracert command to find out where the communication breaks down.

To find a user’s mail server, start nslookup and enter the command set type=MX. Then, enter the domain portion of the user’s e-mail address. For example, if the user’s address is Doug@LoweWriter.com, enter LoweWriter.com. nslookup will display the MX (Mail eXchanger) information for the domain, like this:

C:>nslookup
Default Server:  ns7.attbi.com
Address:  204.127.198.19
> set type=mx
> lowewriter.com
Server:  ns7.attbi.com
Address:  204.127.198.19
lowewriter.com  MX preference = 50, mail exchanger = sasi.pair.com
lowewriter.com  nameserver = ns000.ns0.com
lowewriter.com  nameserver = ns207.pair.com
ns000.ns0.com   internet address = 216.92.61.61
ns207.pair.com  internet address = 209.68.2.52
> 

Here, you can see that the name of the mail server for the LoweWriter.com domain is sasi.pair.com.