The best Calendar alternative to Posteo is Proton Mail, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 50 alternatives to Posteo and 15 are Calendar Apps so hopefully you can find a suitable replacement. Other interesting Calendar App alternatives to Posteo are Tuta Mail, Google Calendar, Proton Calendar and Tuta Calendar.
This secure email platform offers end-to-end encryption, a comprehensive suite with Calendar and Documents. Mailfence is inter-operable with OpenPGP services, features digital signatures, provides keystores, and available as a PWA for mobile independence while ensuring no ads, trackers, or surveillance.
Proton Mail provides secure email services with end-to-end encryption, ensuring data protection. Swiss-based and outside US jurisdiction, it offers a free version to champion privacy as a human right. Fully accessible on any device.
Offers comprehensive encryption for email, calendar, and contacts with zero personal info required. Built on open source, install via Play Store, F-Droid, or APK, with Tor and VPN support. Both free and paid plans; utilizes quantum-resistant encryption ensuring privacy-focused, anonymous usage.
Manage events seamlessly with syncing across devices, automatic event creation from Gmail, shareable schedules, customizable reminders, and a user-friendly interface. Features include dark mode, integration with Google services, and support for recurring events and global time zones.
Your calendar is a record of your life. Proton Calendar helps keep it private.
Tuta Calendar offers secure event organization with end-to-end encryption and no ads or tracking. Enjoy multi-device sync, multiple calendar views, and offline access. Fully compliant with strict German data protection laws. Manage recurring events, unlimited calendars, and seamlessly integrate with Tuta Mail.
E-mail inbox, online office, cloud storage, and video conferencing. Business or personal plans. From 1 € /month (1.10 USD).
Fastmail offers secure email hosting with comprehensive webmail services, including IMAP, POP, and SMTP protocols. It supports file sharing, shared folders, large mailboxes, instant messaging, and is compatible with popular email programs. Excellent for businesses with compliance features.
This secure email platform offers end-to-end encryption, a comprehensive suite with Calendar and Documents. Mailfence is inter-operable with OpenPGP services, features digital signatures, provides keystores, and available as a PWA for mobile independence while ensuring no ads, trackers, or surveillance.
GMX Mail is a German-based free webmail service provided by GMX (Global Mail Exchange). In addition to an e-mail address, each GMX account includes a Mail Collector, Address Book, Organizer, and File Storage.
Vivaldi Mail is a free email service with no ads and no strings attached developed by Vivaldi Technologies. It also offers contacts and calendar features, search capabilities, folders management, WEB/POP/IMAP access, 10GB of storage capacity, 20 MB of maximum attachment size...
Kolab Now provides a suite of intuitive apps in a user friendly environment to make your day to day online comms easier, smarter and most importantly; secure.
Belgium
EU
Switzerland
Germany
United States
Australia
France
Norway
Protonmail, like posteo, is security based email.