OpenChange Alternatives

Zimbra is trusted by over 500 million users to increase productivity with a complete set of collaboration tools while maintaining total control over security and privacy.

Web-based IMAP email client

The #1 email warming service to improve your deliverability by generating realistic and meaningful engagement to your emails. Easy-to-use solution to help you land in the main inbox instead of the spam folder.

Visit website paid $19.5 / Monthly (Pro)

A fully fledged, free email server solution, an open source project (GPL v2).

Horde Groupware is a free, enterprise ready, browser based collaboration suite.

Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft.

Designed for those who settle only for the best — CrossBox is beautiful, dazzlingly fast, and comes with advanced features that provide you and your team with cutting-edge communication technologies.

paid €6.3 / Monthly

Google's encompassing suite of cloud-based business apps.

On-premises, enterprise collaboration solution for documents, emails, calendars and more.

hMailServer is a free e-mail server for Microsoft Windows.

Sharing & communication software for business

RainLoop is a web based email client.

Boost your productivity with reliable access anywhere with services like email, calendar, file sharing, meetings, instant messaging, and Office Online

SOGo is groupware server with a focus on scalability and open standards.