Ask HN: private "email" campaigns for startups software?

We're developing a new project right now and to get more involved with the real people we'd like to selectively email some individuals (example: medical bloggers, who may be interested in the product and help us make it better). I assume we'd have to collect over thousand of emails over time. Obviously it's hard to manage this amount of contacts. Sure, I'll be able to read all the replies, but what I'd like to be able to do is to store the relevant info along with them: names, locations, occupation, number of days it took them to reply, some notes about their replies ("not very interested" or "annoyed" or "excited"), then effectively retrieve and use the contacts again if they qualify and send back some prepared "thank you" emails or other slightly customized replies. Well, you get the picture. Spreadsheet does not really solve the automation problem here. Any software for these purposes?