aaaaaaaaaaaaaaaaand, in Dean's defense.... Listmail is far better than the other software options in other ways... including very hands-on support - wait until you have to pay them hourly at $100/hr to have them fix something that Dean does for free.
Anyways, many of us have come to Listmail after dealing with software like 12All because of the other ways that Listmail shines, depending in people's needs. Sequenced followups, un-encrypted source code, and overall SPEED is why I've stayed with Listmail for over 8 years.
I'm so comfortable with how the software works and is built, that I often build other applications around Listmail's database structure. Almost every application ties in with contact management and sequenced messaging.