Message Composition


Send Later

True "Send Later" functionality to schedule the time for sending an email.

Rated 5 out of 5 stars (39)
58,374 users

Mail Merge Featured

Mass Mail and Personal Mail

Rated 5 out of 5 stars (135)
51,364 users


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!

Rated 4 out of 5 stars (107)
39,245 users


Save frequently-entered text for pasting later.

Rated 4 out of 5 stars (166)
34,490 users

Check and Send

Check the message contents and addresses before you send the message...

Rated 4 out of 5 stars (25)
25,591 users


SmartTemplate4 offers an easy way to automatically create customized replies by auto-inserting various mail headers. Templates can be created for every account as well as for the default (all email accounts). Also supports the Stationery Add-on.

Rated 5 out of 5 stars (49)
18,204 users


ThunderPEC semplifica la gestione della Posta Elettronica Certificata (PEC) in Thunderbird.

Rated 4 out of 5 stars (6)
13,454 users

Transliterator No Restart

As-you-type phonetic conversion of text from one alphabet to another, as well as transliteration/detransliteration of selected text anywhere within documents. Supports multiple languages and custom transliteration schemes.

Rated 5 out of 5 stars (76)
7,152 users

Markdown Here

Write your email in Markdown, then make it pretty.

Rated 5 out of 5 stars (15)
6,590 users


An input method editor (IME) for Vietnamese. Type Vietnamese diacritics directly into any Web page, Web app, or dialog box.
Bộ gõ tiếng Việt cho phép đặt dấu trực tiếp vào bất kỳ trang Web, ứng dụng Web, và hộp thoại.

Rated 5 out of 5 stars (30)
6,269 users

Flex Confirm Mail

Confirm mail address and attachments based on flexible rules.

Rated 1 out of 5 stars (1)
5,794 users

Extra Format Buttons

Adds a font size (in pixels), strikethough, subscript and superscript buttons to Thunderbird's Compose Window.

Rated 5 out of 5 stars (5)
4,077 users

BorderColors GT

How many time you sent an email from your wrong email address?
This add-ons allows you assign a different color to the compose window border for each of your email addresses. So you can immediately view from what account are you writing.

Rated 4 out of 5 stars (7)
3,893 users

SmilieInserter Plus

Insert smilies in messages.

Rated 5 out of 5 stars (17)
3,616 users

Email signature for Thunderbird - WiseStamp

Switch Thunderbird email signatures. Supports Gmail, Yahoo, AOL & Outlook webmails. Youtube, Facebook, Twitter icons & more

Rated 3 out of 5 stars (1)
3,344 users

Automatic Dictionary No Restart

Extension that remembers the language of the spellchecker used when composing and switches to it every time you write to that person.

Rated 5 out of 5 stars (20)
2,586 users


Save your email into Evernote by forwarding it to Evernote email address.
Before you use it, you need to specify your Evernote email address (see the screenshot).

This function can be invoked by "Forward to Evernote" in the context menu.

Rated 5 out of 5 stars (5)
2,276 users

Color Text Compose Buttons

Adds Text Color Buttons in Compose Toolbar and More: Pixel FontSize, Strikethough, Sub & Superscript, Lower & UpperCase. Also provide Tools: Insert iframe, Launch MathType, Maths & Greek Symbols, Load Template Variables and Duplicate Compose Window.

Rated 5 out of 5 stars (15)
1,895 users

hubiC for Filelink

Add hubiC support to Thunderbird's Filelink feature.

Rated 4 out of 5 stars (11)
1,684 users

Flexible Identity

Selects an identity based on the recipients list when sending an email

Rated 4 out of 5 stars (23)
1,678 users