Learn the Basics. Get Started Tot All articles and threads In English Thunderbird and Gmail The difference between IMAP and POP3 How to change the Thunderbird layout Getting Started with the Thunderbird main window (Supernova and newer) Cannot send messages Make Thunderbird the Default Mail Client Ignoring threads Protect your Thunderbird passwords with a Primary Password Installing an Add-on in Thunderbird New in Thunderbird 102 Dangerous directories Unified Toolbar Maildir in Thunderbird Thunderbird Accessibility Features Thunderbird end of Support for XP and Vista Getting started with the Thunderbird main window