Highlights selected text when composing emails. Default colour is yellow - other colours are available via Options.
(Works only during writing an e-mail, i.e. only in the compose window.)
Upload large attachments to your Cloud and send the link by email
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.
Check that number of non-BCC recipients does not exceed a parameter.
Address bulk copy （アドレス一括コピー） Requires Restart
Thunderbird は Outlook のようにアドレス全選択からの「一括コピー」ができません。
Quickly choose one of the previously selected colors for a message text
Stop Ignoring Reply:To Requires Restart
Default "Reply" functionality pays attention to "Reply-To" in original email
Create and Save or Send Multiple Individual and Personalized Messages from a Draft
Adds support for the X-Unsent header.
Macro Template is to replace mail templates with macros for date formatting.
True "Send Later" functionality to schedule the time for sending an email.
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.
Allows you to resend (also known as redirect) email messages.
Uses 'cardbook' if installed
Bases on the add-on 'Mail Redirect' by Onno Ekker and Pawel Krzesniak
Please see the help page on how to use and why it sometimes does not work!
Identity Chooser helps you to always use the correct identity when composing a new email.
Allows you to use your Exchange email accounts that use Outlook Web Access (OWA) with Thunderbird
Warns if you send mail from or to a specified domain. If there are multiple accounts in your profile, you can isolate one so that you can't send mail to that domain from outside or vis versa without warning.
AVIM Requires Restart
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.
A revival of the popular Markdown-Here addon for Thunderbird 78 and beyond.
Markdown Here Revival is a Thunderbird extension that lets you write emails in Markdown and render them as HTML before sending.
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.
With the help of this Add-on, up to 99 pre-made texts (standard texts, text modules or even signatures) can be stored, which can then be retrieved and inserted when writing an e-mail.
The texts can be preformatted with HTML.