So it turns out the extension/mailbox i was using is a Virtual IT DOESN'T WORK WITH VIRTUALs!

It does work with a physical extension port and mailbox. Which is what we wanted it to do, I was just using a virtual in my testing so i wasn't bugging anyone at the site with ringing phone.

Thank you guys for the response. I shoulda posted back but totally forgot about it.

Thank you,
Gary Frisco