If you have a Windows system, you probably have Access, which is a perfectly good database program – use it? You can draw reports, publish listings, establish relationships, all with a stock Microsoft product. Do not make it more difficult than it has to be.
Constant Contact is a good one. I hear ACT is as well.
If you are looking for an actual person to send out emails/letters for you, and just manage the list in general, my company offers that service, regardless of your location.
Contact me if interested! Thanks.