Message Composition


Mail Merge Featured

Mass Mail and Personal Mail

Rated 5 out of 5 stars (134)
2,112 weekly downloads


Save frequently-entered text for pasting later.

Rated 4 out of 5 stars (166)
2,014 weekly downloads

Send Later

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

Rated 5 out of 5 stars (39)
1,533 weekly downloads


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)
736 weekly downloads


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)
555 weekly downloads


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

Rated 4 out of 5 stars (6)
553 weekly downloads

Markdown Here

Write your email in Markdown, then make it pretty.

Rated 5 out of 5 stars (15)
418 weekly downloads


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)
406 weekly downloads

Check and Send

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

Rated 4 out of 5 stars (25)
389 weekly downloads

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)
308 weekly downloads


Category manager for CardDav contacts, also allows to send an email to all members of a category (categories can be used as contact groups).

Rated 5 out of 5 stars (6)
293 weekly downloads

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)
202 weekly downloads


Easily and quickly to encrypt / decrypt
For users: private messages via e-mail, blogs, social networks, forums, etc.
For webmasters: websites, images, photos, etc.
Support: Firefox, Thunderbird and SeaMonkey

Rated 5 out of 5 stars (6)
192 weekly downloads

Emoji Menu

Adds the ability to easily insert emojis into your composed messages in Thunderbird.

Rated 4 out of 5 stars (1)
182 weekly downloads

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)
171 weekly downloads

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)
90 weekly downloads

DL for Thunderbird

Allows to convert large attachments to links automatically without 3rd party providers.

Rated 5 out of 5 stars (3)
71 weekly downloads

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)
71 weekly downloads

Consigna para Filelink

Plugin para subir ficheros a Consigna (Junta de Andalucía) de forma automática desde Thunderbird.
Está ideado para el intercambio de ficheros de gran tamaño. Es un espacio de almacenamiento temporal y con algunas restricciones de acceso opcionales.

Rated 5 out of 5 stars (1)
67 weekly downloads

hubiC for Filelink

Add hubiC support to Thunderbird's Filelink feature.

Rated 4 out of 5 stars (11)
64 weekly downloads