The best Calendar alternative to OpenMailBox is Proton Mail, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 25 alternatives to OpenMailBox and 12 are Calendar Apps so hopefully you can find a suitable replacement. Other interesting Calendar App alternatives to OpenMailBox are Tuta Mail, Posteo, mailbox and Fastmail.
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.
Web- and IMAP-based email service. 4GB cost 1€/month. Information is hosted on encrypted hard drives. Electricity from renewable resources is used.
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.
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...
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.
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
Australia
Norway
France
United States
Decent free space, great reliability and data encryption.