The MozQA community is holding a Testday on Friday, May 28th, for users interested in the use and development of Mozmill with their Firefox Add-ons! We're going to have the Mozmill team available to help people, perform exploratory testing on Mozmill and just generally chat about the project for the community via IRC Chat (channel #testday on irc://irc.mozilla.org). So, if you're interested, come on by anytime between 7AM to 5PM PDT that Friday!