SeventyMail
SeventyMail
Your emails in your language. Your replies in theirs.
SeventyMail translates the message shown in Thunderbird in one click, and corrects, rewrites or translates what you write. Claude or ChatGPT, three levels of precision, layout and signature left untouched. Free 7-day trial.
SeventyMail for Outlook is on its way
Same features, for Outlook on Windows, Mac and the web. Meanwhile, the Thunderbird extension works with all your accounts, including Outlook.com, Microsoft 365 and Exchange.
Install in one minute
Download the SeventyMail.xpi file with the button above.
In Thunderbird, open the ≡ menu then “Add-ons and Themes”.
Click the ⚙ gear then “Install Add-on From File…” and pick the downloaded file.
Confirm with “Add”. The SeventyMail buttons appear above every message and in the compose window.
Shortcut: ⌘ ⇧ A on Mac, Ctrl ⇧ A on Windows and Linux. You can also drag the file onto the add-ons page. Updates then arrive on their own.
Everything you need to write abroad
Translate while reading
One click on a received message: it shows in your language, layout included. A second click brings back the original.
Fix mistakes
Spelling, grammar and punctuation, without touching your style or your language.
Rewrite
Clearer, more professional text, following your own instructions: tone, length, greetings.
Translate before sending
You write in English, the recipient reads in German, French or Thai.
Signature spared
Your signature and the message you reply to stay untouched, and cost nothing.
Confidential
Content goes through our Swiss server to the AI and is never stored.
Pay for what you use
A lifetime licence, then credits you top up whenever you like, from 5 CHF. The price depends on the level you pick. You can also plug in your own Claude or ChatGPT key: the provider then bills you directly.
Buy the licence
… CHF, once, forever. Key sent by email.
Frequently asked questions
Are my emails stored anywhere?
No. The text to process goes through the Seventy Labs server in Switzerland to Claude or ChatGPT, and the answer comes back to Thunderbird. Nothing is stored or logged, and the providers do not train their models on data sent through their API.
How much does one email cost?
Almost nothing: a typical email costs a fraction of a cent at the Fast level. The exact price of each operation shows in the banner, and your remaining credit in the extension window.
Are my signature and the original message translated?
No, by default they stay untouched. You can change that in the settings if you want them processed too.
Does it work on Windows and Linux?
Yes. SeventyMail is a Thunderbird extension, it works wherever Thunderbird 128 or newer runs: Windows, macOS and Linux.
How do updates work?
Automatically. Thunderbird checks for new versions and installs them without asking you anything.