Official Thunderbird plugin
Encrypted file transfer from Thunderbird.
End-to-end encryption, open-source code, hosting in France. The Retyc plugin for Thunderbird encrypts your files on your device before sending. No one, not even Retyc, can access their content. Your recipients receive a simple download link in the email, no account required.
How it works
Three steps, without changing any of your habits.
The plugin integrates directly into Thunderbird. You keep writing emails exactly as before.
1. Write your email
Open a new message in Thunderbird, just as you normally would.
2. Attach your files via Retyc
Click the Retyc button in the toolbar and select your files. They are encrypted on your device before being sent.
3. Send your message
The email goes out normally, with a secure download link. The recipient clicks, downloads — no account required.
Privacy
Why choose Retyc for Thunderbird?
Privacy, transparency, and open code — without compromise.
Encrypted on your device before sending
Your files are encrypted on your machine before being transmitted. Neither the network nor our servers see their content.
Your files are inaccessible to us
Names, contents, and metadata are encrypted on your side. Retyc has no way to access your data.
Open-source code
The plugin code is public and auditable by anyone. No blind spots in the software — you can verify exactly what it does before every send.
Hosted in France, GDPR-compliant
Your data stays in France, with European providers. No exposure to the CLOUD Act or US law, within a clear and lasting framework.
Also
Simple for you, simple for your recipients
From installation to receipt, every step was designed to stay seamless.
No size limit
Send lightweight documents and heavy archives alike. Your mail provider's attachment caps no longer apply.
No action required from recipients
Your contacts receive a link in the email. They click and download. No sign-up, no app to install.
Links expire automatically
Set a validity period for each transfer. Once the deadline passes, files are automatically deleted.
Who it's for
For those who want to be able to verify
Retyc integrates with Thunderbird for users who chose an open-source email client because they care about their privacy and the transparency of their tools.
Legal professionals and advisors
Client files, sensitive dossiers, confidential exchanges. End-to-end encryption and EU hosting, verifiable right down to the code.
Finance and accounting
Financial statements, payroll, M&A files. No volume limits and clear traceability for every transfer.
IT and security teams
Open-source code, end-to-end encryption, hosting in France. A solution your security team can audit themselves, line by line.
Install the plugin and send with confidence.
Create your Retyc account, install the Thunderbird plugin, and send your first secure transfer in a few minutes.
Frequently asked questions
Thunderbird 115 or a more recent version. The plugin is a standard Thunderbird extension, so it follows whichever systems your client runs on.
From addons.thunderbird.net, where the extension is published. You add it like any other Thunderbird add-on, and the Retyc button appears in the compose window.
Yes, it is published on GitHub. You can read it, check what it does with your messages and propose fixes.
On the first send, the plugin shows an address and a code. You open the address in a browser, identify yourself, enter the code, and that is settled for the future.
No, neither Thunderbird nor anything else. The link they receive opens in a browser, and decryption happens there.
Never. Encryption happens inside the plugin, on your machine, and the key is not passed to us. What we store in France is unusable without it.
The plugin sets no per-file ceiling; it is your Retyc plan that determines the allowance available to you. Enough to move attachments well beyond what a mail server will accept.