I have just finished a new version of Spam Control, v0.2.3, which includes the ability to hide categories of email addresses from the pop-up menu (leaving it as uncluttered as possible). This version also fixes a bug where the list of domain prefixes or suffixes is empty.
Download Spam Control 0.2.3 here.
If you like it, please make sure you go to the Firefox add-on page and add a review – that way, it may eventually make it out of private-beta-obscurity on the site and be shown to anyone looking for what it does. Until then, it can only be found by people like yourself who find my blog, or by users that bother to log in 🙂