Tuta

Tuta (formerly Tutanota) is an end-to-end encrypted email service operated by Tutao GmbH from Hanover, Germany. Subjects, bodies, attachments and contacts are encrypted on-device, and the service uses its TutaCrypt protocol with post-quantum cryptography. There is a free 1 GB plan, paid personal plans from EUR 3/month and business plans from EUR 6/month, with desktop apps for Windows, macOS and Linux plus iOS and Android. The product range now also includes Tuta Calendar and a Tuta Drive cloud storage beta. Software is open source.