True "Send Later" functionality to schedule the time for sending an email.
Mail Merge Featured
Mass Mail and Personal Mail
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!
Save frequently-entered text for pasting later.
Check the message contents and addresses before you send the message...
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.
ThunderPEC semplifica la gestione della Posta Elettronica Certificata (PEC) e delle comunicazioni PCT e FatturaPA in Thunderbird.
Confirm mail address and attachments based on flexible rules.
Quickly highlight some text in Thunderbird message composing windows.
Write your email in Markdown, then make it pretty.
Toggle word wrapping and PRE element wrapping in the message composition and HTML display windows, respectively.
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.
Adds a font size (in pixels), strikethough, subscript and superscript buttons to Thunderbird's Compose Window.
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.
Switch Thunderbird email signatures. Supports Gmail, Yahoo, AOL & Outlook webmails. Youtube, Facebook, Twitter icons & more
Insert smilies in messages.
Adds the ability to easily insert emojis into your composed messages in Thunderbird.
Vietnamese-language input method editor (IME). Type diacritics directly into any Web page, Web app, or dialog box. Convenient, comprehensive, secure.
Bộ gõ tiếng Việt cho phép đặt dấu trực tiếp vào bất kỳ trang Web, ứng dụng Web, hộp thoại.
Automatic Dictionary No Restart
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.