if you are serious about mailing, then your best solution is to do it all inhouse. Get a dedicated server, put some email software on it (we use icewarp
www.icewarp.com ), there is a ton of mailing list software, mostly inexpensive. Its not hard to do, if I can do it anyone can. we have been running our own mailer for about 15 yrs. email me if you have questions, there are some things I wont post on here.