Rated 5 out of 5 stars

The Mass Mail option is a nice alternative for BCC, and you can edit the mail for each recipient if you wish. But the Personal Mail option is what makes it really great for me. It uses as many fields from a .csv as you want, so it can be quite powerful if you prepare it well. For large mailings you end up with a lot of sent mails in your Sent folder, but it uses the Local Folders for that (which I don't use), so on my setup it has its own playground there.

This review is for a previous version of the add-on (1.0.2).