Reply to an EMAIL get posted in a mySQL TABLE

Hi gang, I use a Project Management System (PM) that generates emails to my account. I can REPLY to that email and it will be inserted into the PM. I believe the ID is in the subject. I assume the email is sent to a specified email and there is a CRON JOB that runs a PHP script to query and parse the new emails and insert them in to DB. Obviously a cool feature, that I want to use in a few of my web apps. Anyone have any tips/resource links or a product I can use to do this. Any feedback is appreciated! Don