I've worked with a multitude of bulk email programs over the past 6 years and they all have their pros and cons. There didn't seem to be one that could do it all for me and some are so convoluted I just never got started or I spent loads of hours setting them up only to find out I needed to buy something before I could send 1000's of emails.
Maian Responder is self-hosted, feature packed yet simple to use and once you have installed and setup the system (which is very easy) you can fire away emails without worrying about escalating costs or email limits. Obviously, managing your own reputation carefully is a prerequisite but any legitimate email sender will understand this and not expect software to compensate for reckless email spamming.
Used in conjunction with Amazon's SES as your SMTP you can happily send 2000 emails a day (for FREE) without worrying about a thing.
If you are sick of hunting for a decent self-hosted option, buy Maian Responder and start marketing instead of cobbling together bad solutions.
Julio Graham (Managing Director - Olive Professional Services Ltd)