Thunderbird Send

FileLink provider for Send

Thunderbird add-on/MailExtension to easily and securely encrypt and upload large attachments to any Send service instance (formerly Firefox Send) and send the links via e-mail using the CloudFile/FileLink API. Firefox Send was discontinued by Mozilla in 2020. It is now maintained by @timvisee and called just Send, but soon will be resurrected by Thunderbird.

Enables simple, yet private file sharing with end-to-end encryption
Files are securely encrypted and uploaded locally in Thunderbird using the Web Crypto and WebSocket APIs
Files are encrypted and uploaded in chunks, so it requires very little memory (RAM) for even large files
Links are automatically added to the e-mail by Thunderbird when uploads finish, which includes the encryption secret needed to decrypt the file
When recipient clicks a link, the file will securely download and decrypt locally in their browser using that encryption secret
Links automatically expire after the download and time limit
Desktop notifications when the uploads start and finish
Users can specify the Send service instance(s) to use, defaults to the one provided by @timvisee: https://send.vis.ee
Users can specify the download and time limits for each file and defaults for each Send service instance
Users can optionally protect each file with a password
Can securely generate a strong password or passphrase
Supports the maximum file size supported by each Send service instance, currently 20 GiB
Supports canceling the uploads
Supports deleting the files from server after uploads finish
Supports all v3 (or greater) Send service servers/instances
Does NOT require a Firefox Account (FxA) or any other accounts, all uploads are anonymous
Supports the light/dark mode of your system automatically
Follows the Thunderbird Photon Design
Translated into two languages

More information on the encryption used can be found in the official Send service documentation here.

❤️ Please visit tealdulcet.com to support this extension and my other software development.

This add-on is not affiliated with Mozilla, Firefox or any Send service instance.

Download

Clone the repository:

git clone --recurse-submodules https://github.com/tdulcet/Thunderbird-Send.git

Translate the add-on using the online WebExtension Translator and then open a pull request or issue with the resulting translations. Please see this guide or the official documentation for more information.

Pull requests welcome! Ideas for contributions:

Convert to Manifest V3 (MV3)
Refactor into more modules
Open the popup in the compose window instead of a separate standalone window (see Bug 1711446 and Bug 1752114)
Show the upload progress (also see Bug 736169)
Support consolidation/zipping of multiple attachments into a single link (see Bug 1856232)
Improve the management page
- Check validity of input before saving values
Sync settings (see bug 446444)
Support showing notifications in the notification bar (see Bug 1674002)
Support Firefox Account (FxA) authentication (see here)
Improve the performance
Integrate this functionality into Thunderbird (see Bug 1516252)
Create a Firefox/Chrome add-on/WebExtension to both upload and download files