Help with creating mailing lists

I would like to invite/send newsletter to a known set of email addresses. I have these addresses
in a worksheet at the moment, but the goal is to register these addresses "somewhere" in Drupal db
and use them to send a newsletter and invite new users. I have looked at different modules, but haven't
found a suitable module yet. I want something simple.. From what I can see, most modules (recipient_lists,
mass_contact, buddy list, og2mlm etc) seems to work based on roles/users. Can I solve this issue without having to create "fake" users with real emails and grouping them in different roles?

BTW, the list of users will be saved in main site and they are invited to create accounts in sub sites (multisite setup with prefixed database tables).

Mike
www.sameieportalen.no