Techeez.com

To Test a mail server from the command line:

First you need to telnet to port 25 like this
telnet ip address 25

Then

ehlo mydomain.com
mail from:martin9700@anydomain.com
rcpt to:jack@mydomain.com
data
This is a test, please do not respond
.
quit

You will need to type this in exactly as above or the mail server will kick you out.