Forum Moderators: phranque
bulk emailers
mass emailers
I don't particularly trust most of them since they are so close to the spam world, but I've used one for years, I don't want to mention it by name because as I noted, I don't quite trust the people who write these.
But these things work very well, it's very easy to use them, and they send real individual, personalized emails, great tools. There might even be an open source one by now, haven't checked.
Majordomo is a much more complicated setup, I can't remember how hard it is to setup, and it's kind of overkill.