Hey Dink -
First off, my blaster is a two-piece php app like my crawler that I can throttle appropriately. So for example, often my underwear sites go out at as few as 3 mails per minute, where a weekly schedule may be scheduled for 100/minute.
Some important things to do:
* Develop a relationship with an ISP where they can assist you with spam control - preferably someone with SpamAssassin. This lovely little piece will nab you for the tiniest things... but if you've a good relationship, then your ISP can tell you exactly why you're failing to get through. Sometimes it's really silly, sometimes really obvious.
* If you go HTML, make sure you have a corresponding Text email on it as well - this is a common spam trap
* Understand greylisting. Go here:
http://en.wikipedia.org/wiki/Greylisting* From a per-delivery success perspective, customize whatever you can. Use their name, past experience, site they've been to, whatever you can to associate you with something they remember and they will be less likely to circular file you.
* I am told that most servers are starting to employ a velocity engine pretty hard ie., too many emails to one domain too fast and you're bagged. Personally, I am considering restructuring my sends to say "I want all my emails out in 6 hours - given I have 13,000 cox.net addresses, what is the slowest spread I can do for each of them" - so rather than sending out all emails in alphabetical order, I'll send spread out by domain trying to minimize the speed with which I hit any particular one.
* Keep your list clean - the more times you hit a domain with the same bad address (or any bad ones for that matter) the more likely they are to see you as a bad boy and can you.
* If you can send from the defined MX record machine and have a SPF record in the DNS for that box as well you're way ahead of the game.
One of the reasons I rolled my own, is that it is connected to my List Manager, which allows us to gin up custom lists of people on the fly - then merge something, blast something - you name it. This is all dynamic and pretty complicated stuff, so no - a commercial solution was not viable. Additionally, the "blessed distributors" that charge you (x) per send are strong, but really expensive by comparison.
Hope that helps...
