How to make MailComment work.

I need some help with Mailcomment.
I have a project that is a simple workitem tracking system.
I would like outside users to get email when comments are added to their workitems and then be able to reply via email. The email system we are using is Outlook.
So I am struggling with the MailComment module. I can send the email to the user with the tag line ((( Reply ABOVE this LINE to POST a COMMENT ))).
But I can’t for the life of me figure out how to get the reply to work.
Any help would be greatly appreciated.

Module list:
Drupal core 6.26
Chaos tools 6.x-1.9
Feeds 6.x-1.0-beta13
Feeds Comment Processor 6.x-1.0-beta2
Mail Comment 6.x-2.3
Mail Handler 6.x-2.5
Messaging 6.x-2.4
Notifications 6.x-2.3