mailbox (formerly mailbox.org) vs Tuta

German paid digital workplace from Heinlein Hosting GmbH: secure email with PGP/S/MIME, Drive, browser Office, Meet, and business Admin on dual Berlin data centres.

German end-to-end encrypted email, calendar, and contacts from Tutao GmbH in Hanover—with post-quantum TutaCrypt, open-source clients, and freemium personal plus business plans.