← オープンソース代替
ProtonMail のオープンソース代替
ProtonMail を置き換える無料・OSS・DL可能な選択肢
End-to-end encrypted email with calendar and contacts — Tuta is an email service with a strong focus on security and privacy that lets you encrypt emails, contacts and calendar entries on all your devices.
代替: Gmail、Outlook、ProtonMail
8k+8/日GNU General Public License v3.0チャットとメールtutao/tutanota