Kolab Now Alternatives for Online

ProtonMail is an end-to-end encrypted email service.

Tutanota is an open-source end-to-end encrypted email software and freemium hosted secure email service.

ZOHO Corporation offers online business, network, and IT infrastructure management applications, and software maintenance and support services.

Yandex.Mail is a free email service.

Yahoo! Mail, a web-based email service, launched in 1997 through the American parent company Yahoo!. Yahoo! Mail provides four different email plans: three are for personal use (Basic, Plus, and Ad Free) and another is paid-for business use.

Mailpile is a webmail client with encryption and privacy features built-in. Mailpile is free and open-source software.

Zoho Mail is a email service with ample storage, POP and IMAP access, some integration with instant messaging and online office suites.

FastMail is an email service offering paid email accounts for individuals and organizations.

Zimbra offers an open source email platform for the enterprise.

Kopano is an open-source groupware application suite originally based on Zarafa.

Wimi is a collaborative platform, for file sharing and online project management.

Microsoft SharePoint is a browser-based collaboration and document management platform.

Hushmail is an encrypted proprietary web-based email service offering PGP-encrypted e-mail and vanity domain service.

Posteo is an email service provider offering paid email accounts for individuals and businesses.

Mailfence is a web-based email service that offers OpenPGP based end-to-end encryption and digital signatures.

Microsoft Exchange Server is a mail server and calendaring server.

AOL Mail (Aol Mail) is a free web-based email service.

WorkSpace collaborative suite for SMEs.

Soverin is a secure mail hosting platform.