CiviCRM Email Setup Joomla

I am running into some difficulty configuring the bounce-back processing part of the CiviCRM email system.

In the manual it tells me to test my script by visiting this site:

Needless to say some changes were necessary to get this to work. For joomla, the path above is almost completely wrong… mine begins with:

But I am getting an invalid user/password error.

Question: Given Dreamhost’s set-up is my username “bounce” or ""? Can I test this by invoking EmailProcessor.php in a php cli instead of the web? (and if so, how)

Any advice on setting this up will be greatly appreciated!