Tuta

Tuta (formerly Tutanota) is an encrypted email service developed by Tutao GmbH, a company founded in 2011 in Hanover, Germany. The name derives from the Latin words for "secure message", and the service positions itself as one of the most privacy-focused mail providers available.

Tuta encrypts not only message bodies but also subject lines, calendars and contact lists — going further than most competitors. The entire client is open source and the company has published its own post-quantum encryption protocol. Free accounts are supported by paid tiers rather than advertising.

The company is independent, employee-owned and runs its data centers exclusively on renewable energy in Germany, which places all user data under German and EU privacy law. Its uncompromising stance has costs: there is no IMAP support, so mail can only be read through Tuta's own apps.