Best email setup for new MU users


I'm looking for the best setup for email I can get, so I decided to ask the users who are experienced already.

So here is my scenario I'd like to create. Open to suggestions.

1. Email Network Users about network updates and new plugins. I've already setup mass email sender. Alternatives with rich html editor?

2. Autoresponder system for new users. I would like to follow up with a series of emails to help their setup in their new site. With options of unsubscribe for the users.

3. A general newsletter setup that's unrelated to the 1st and 2nd option.

Problem I see is if they unsubscribe from 1 of the options how would I control it. I think it would get confusing.

Thank you for your help!
Happy Holidays.