Wow, this rocks! And updates are so fast!!! Rated 5 out of 5 stars

Wow, I can't believe it! You added another service!!! So fast! Thank you so much!

As for tempomail, there is an addon here already from tempomail themselves. So maybe they give you the source or maybe it's easy to find out what it does by observing what the addon does. I don't know much about coding, but as far as I've seen it's possible to unpack the xpi and look what's inside. And it's obviously under GPU license.
http://addons.mozilla.org/en-US/firefox/addon/3883

And here's the English version of their website:
http://tempomail.fr/index_en.html

Thanks again so much! This is really the best anti-spam email addon out there!

This review is for a previous version of the add-on (0.2.7.0).