Summarized Changelog

• Add a hook to allow calling a command each time the unread count changes
• Add an option to ignoring all currently unread emails when clicking on the Birdtray icon to hide Thunderbird
• Birdtray now detects and rejects icons with an invalid color profile
• Fix Birdtray on Linux sometimes thinking the Thunderbird window is hidden when it is not
• Fix Birdtray hanging on startup if a watched Thunderbird mail account was deleted

Full changelog here

• Send some test emails, get notified when they arrive
• Note new option available for ignoring currently unread email