Below are instructions on how to test SMTP AUTH against a mail server using Telnet and entering the commands by hand.

The first thing you need to do is get a base64 encoding of your username and password. There are a couple ways to do this, the example below uses Perl:

website to help with conversion:  http://www.hcidata.info/base64.htm

@ symbol was messing with perl

What will be returned from each command is a base64 encoding of the username and password; save these as you will need them later. Now connect to the mail server using Telnet:

Greet the mail server:

Tell the server you want to authenticate with it:

The server should have returned 334 VXNlcm5hbWU6; this is a base64 encoded string asking you for your username, paste the base64 encoded username you created earlier, example:

Now the server should have returned 334 UGFzc3dvcmQ6;. Again this is a base64 encoded string now asking for your password, paste the base64 encoded password you created, example:

Now you should have received a message telling you that you successfully authenticated. If it failed your user/pass may have been wrong or your mailserver is broken.

Below is a log of a real successful SMTP AUTH connection over Telnet: