Email & Calendar (4)

Mailbox.org

Email & Calendar

Privacy-focused email provider from Berlin with integrated cloud office, calendar, and address book. Runs on 100% green energy with servers exclusively in Germany.

Countries

Data Residency

EU

Open Source

No

Self-Hostable

No

Open-Xchange

Email & Calendar

Open source email, communication, and collaboration platform powering major European email providers. Offers OX App Suite for self-hosted enterprise deployments.

Countries

Data Residency

EU

Open Source

Yes

Self-Hostable

Yes

Proton Mail

Email & Calendar

Encrypted email service based in Switzerland with zero-access encryption. Part of the Proton ecosystem including calendar, drive, and VPN services.

Countries

Data Residency

Non-EU

Open Source

Yes

Self-Hostable

No

Tuta

Email & Calendar

End-to-end encrypted email and calendar service from Germany. Encrypts the entire mailbox including contacts and calendars with a focus on privacy and GDPR compliance.

Countries

Data Residency

EU

Open Source

Yes

Self-Hostable

No