Organize your schedule and life's important events in a calendar that's fully integrated with your Thunderbird email. Manage multiple calendars, create your daily to do list, invite friends to events, and subscribe to public calendars.
Contact Tabs enhances Thunderbird to give you quick access to all your contacts directly from Thunderbird's main window: Use the powerful search field to find your contacts and open them in a new tab for viewing and editing.
This extension allows you to manually sort (order) your folders in the folder pane of Thunderbird or automatically sort them, but in a better way. This extension also allows you to re-order accounts in the folder pane.
German dictionary igerman98 (de_DE, Germany), for Firefox, Thunderbird und Seamonkey.
True "Send Later" functionality to schedule the time for sending an email.
Quicktext is an extension for Thunderbird that lets you create templates that can be easily inserted into your own emails.
If you have duplicate messages (e.g. from merging folders or downloading messages several times) you can use this tool to find and remove them from the selected folder and its subfolder by rightclicking on a folder and choosing "Remove duplicates..."
Add symbol in header plane to switch between compact and expanded view. Options to switch between one or two lines compact view, which buttons should be displayed in header pane. For Thunderbird 36 and older use version 2.0.9 (see version history)
The "Swiss army knife" of folders. Turn your favorites into tabs - open folders and subfolders, move mails without scrolling around or searching. powerful + easy.
See new mail at a glance after automatic filtering - supports quickFilters addon!
Facilitates handling of duplicates in your address book(s). Allow to search and remove similar contacts.
Your browser trusts many certification authorities and intermediate sub-authorities quietly, every time you enter an HTTPS web site. This add-on reveals when certificates are updated, so you can ensure it was a legitimate change.