Tutanota

Tutanota is an open-source email client prioritizing privacy with end-to-end encryption for emails, contacts, and calendars. No ads or tracking—client-side encryption ensures even Tutanota can’t access your data. Seamlessly integrated with macOS, it offers a clean interface and offline access. Ideal for privacy-conscious users, it supports custom domains, with a free tier for basic needs and premium plans for extra storage or custom addresses. Open-source code allows independent audits, reinforcing trust in its security measures.