[horde] Question regarding creating a new class

[Mike Poznecki]

Hi,
I am trying to create a custom transport.  
Here are the files that I have created/modified:
created:/usr/share/pear/Horde/Mail/Transport/mySMTP.php
modified:/var/www/horde/config/conf.xml

But when I try to select it in the config page, I receive an error that says:
 
 "mySMTP" driver (for Horde_Mail_Transport not found). [on line 85 of 
 "/usr/share/pear/Horde/Core/Factory/Base.php"]
 
 What else must I do besides creating the file with my class and setting 
 up the conf.xml with the name of my class (minus the Horde_Mail_Transport) ?
 
 Is there something else I need to do in order for Horde to know about my 
 class?
 
 Thanks,
 Michael.