Add-ons
Message Composition
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LSP Rewrap
LSP Rewrap cleans up plain-text emails by collapsing extra spaces, tabs, and other spacing issues—like older Thunderbird versions did. Use the toolbar button, Ctrl+Shift+R, or Tools → LSP-Rewrap while composing a plain-text message.
Strikethrough Button
Adds a strikethrough toggle button to the Thunderbird compose toolbar. As this is an extension, it is not an integrated component of the Thunderbird toolbar. That is why it sits at the far right on the toolbar and not next to the B/I/U buttons.
SmartQuotes
Applies the correct smart quotes („ ... “ instead of " ... ") used in Lithuanian, German, Czech, and other Central European languages. One click fixes your entire text.
ReplyAgent
SAGE
This extension checks before sending an email that the type of the attached files is allowed and that the total size of the attached files respects a maximum limit. SAGE is the acronym for Safe Attachment Guard Extension.
Paste Files as Attachments
This Thunderbird add-on fills the gap left by the modernized Attach-From-Clipboard add-on, which is no longer able to paste files from the clipboard as attachments after migrating away from legacy Mozilla code.
TidySubject
FlexConfirmMail
Confirm mail address and attachments based on flexible rules.
This edition will have incompatible changes. Another edition for enterprise users with less changes:
https://addons.thunderbird.net/thunderbird/addon/flex-confirm-mail-stable/
Search Selector
Плагин для выбора поисковой системы при поиске выделенного текста.
Auto Capitalize Mail
Quicktext Community Scripts
A set of Quicktext scripts maintained by the community
Inbox Actions
Inbox Actions add convenient interactions to messages allowing users to interact with an product or service all without the user even having to open their email.
Thunderbird-CloudLink
Inserting file link to mail with optional password and expiration date
Webbuttons - Google Messages Web
Adds a button in the toolbar for Google Messages Web. Icon source: https://www.flaticon.com/free-icon/comment_9449200
OpenAI Proofreader
This extension uses OpenAI gpt-4o-mini to proofread emails when the user clicks the extension icon.
Usage requires an OpenAI API key. OpenAI does not offer a free usage tier. Proofreading a 4-5 paragraph email costs a fraction of a cent.
Gemini Proofreader
This extension uses Gemini Flash 2.0 to proofread emails when the user clicks the extension icon.
Usage requires a Gemini API key. There is a free usage tier that should be more than adequate for almost every user.
Reply with Attachments
Automatically include attachments in email replies.
Skips SMIME certificates to avoid unnecessary attachments
Fügt automatisch Anhänge aus der ursprünglichen E-Mail hinzu.
Überspringt SMIME-Zertifikate, um unnötige Anhänge zu vermeiden.
ThunderAI Sparks
ThunderAI Sparks is an add-on designed to add advanced features to ThunderAI.
addy.io / AnonAddy for Thunderbird
Adds a button to the message composition window which updates recipient addresses to route the outbound message through addy.io or a self-hosted AnonAddy server, so your real, private email address isn't exposed to recipients.
Daily Reports
This plugin lets you store different profiles with CC, To, Subject and Signature values. Perfect if you need to send emails with similar details often.
To create your own collections, you must have a Mozilla Add-ons account.
