That's what I had thought; doing a little more digging I found:
http://portal.smartertools.com/kb/a2942/cannot-activate-smartermail.aspx?KBSearchID=613288
Permissions with the Network Services account on the SM folder/files.
Also found a typo in my firewall rule... which was probably the real culprit!
Thanks for the assistance.
My Other suggestions: http://bit.ly/segoideas