Microsoft Exchange Server 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.

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

Open Source

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)

An open source mailserver suite.

Open Source

Web-based IMAP email client

Open Source

9 hours ago - It does include a proprietary software set optimized for business users, students, researchers and developers." A list of features and further details can be found in the company's release announcement.

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

Postfix is a mail transfer agent (MTA) that routes and delivers electronic mail.

Home, overview and getting started with Puppy Linux, amazingly fast, fascinatingly complete and delightfully small Linux.‎Wiki · ‎Download latest Puppy Linux .

Modernisieren Sie Ihre Infrastruktur mit SUSE Linux Enterprise Server, OpenStack Cloud-Technologie für IAAS und softwaredefiniertem Storage von SUSE.

DeLicate Linux is a free and lightweight Linux Kernel-based operating system that is intended for computers comprising of very Low RAM.

Haiku is an open source OS catered specifically to the needs of personal computing.

Open Source

SUSE is the original provider of the enterprise Linux distribution and the most interoperable...

Fuduntu is an open-source appropriation of Linux, a remix of the Fedora working framework, which thusly depends on the honor winning Red Hat Enterprise Linux OS.