Clippings Requires Restart
Save frequently-entered text for pasting later.
Nextcloud for Filelink Requires Restart
"Nextcloud for Filelink" is an Open Source Thunderbird extension which makes it easy to send large attachments with Thunderbird by uploading them first to a Nextcloud server and by then inserting the link into the body of your email.
Send Later Requires Restart
True "Send Later" functionality to schedule the time for sending an email.
Auto Resize Image Requires Restart
Resizer for inline and attachment images (JPEG, PNG, BMP and GIF image formats).
All platforms are supported (Windows, Linux and Macintosh).
SMTP Switch Reborn Requires Restart
Stop Ignoring Reply:To Requires Restart
Default "Reply" functionality pays attention to "Reply-To" in original email
Mail Merge Requires Restart Featured
Mass Mail and Personal Mail
Stationery Requires Restart
Extension to mimic Outlook Express Stationery.
Allow you to use HTML files as templates for mail. Also allow custom template in replies or forwarded mail!
Emoji Requires Restart
Add emojis to your e-mails.
Signature Switch Requires Restart
Switch the signature on/off or choose a new one from your predefined set...
Remembers the language you use with a person or group of people, and switches the spellchecker language automatically for you next time. You do not have to do it manually any more. It remembers and switches it for you.
ThunderHTMLedit Requires Restart
Thunderbird HTML editor. This add-on adds a HTML tab to the composition window where you can see and edit the HTML source of the message.
Custom Address Sidebar Requires Restart
Allow you to help address sidebar more useful.
Markdown Here Requires Restart
Write your email in Markdown, then make it pretty. NOTE: This is the legacy XUL version, for Thunderbird, Postbox, Pale Moon, etc. *Not* for modern Firefox; for that use this: https://addons.mozilla.org/en-US/firefox/addon/markdown-here/
Add menu commands for replying to multiple messages at the same time.
mms Auto Correct Requires Restart
AutoCorrect for the Compose window.
One-by-One Forward Requires Restart
Highlight multiple emails, right-click, then select "One-by-One Forward". This extension will allow you to forward the selected emails, one-by-one, to the recipients you specify using your choice of attachment handling.
MultiTemplateLoader Requires Restart
Manages & applies multiple HTML templates when creating/replying messages.
Templates may be either local files or online links (http:// or ftp://). Up to 9 templates can be defined and easily switched, also using shortcut keys.
ThunderPEC Requires Restart
ThunderPEC semplifica la gestione della Posta Elettronica Certificata (PEC) e delle comunicazioni PCT e FatturaPA in Thunderbird.
ReplyWithHeader Requires Restart
Outlook style headers and few goodies for Thunderbird & Postbox.