How to find out SMTP server

In command prompt, type nslookup and hit enter

> set type=MX

Type the domain name and hit enter, for example

> AD

The results will be a list of host names that are set up for SMTP

Server:  xxx.xxx.com

Address:  xxx.xxx.xxx.xxx

or, under nslookup prompt, type

> set q=mx 

> mailhost