OpenChange!

Zimbra Collaboration is an open, secure collaboration tool for email, calendaring, tasks and more. With the most innovative web application available today, Zimbra boosts the productivity of users on any desktop and dramatically reduces TCO compared to legacy platform vendors.

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

Microsoft Exchange Server is a messaging and collaborative software product developed by Microsoft. It is part of the Microsoft Servers line of server products and is widely used by enterprises using Microsoft infrastructure solutions. Exchanges major features consist of electronic mail, calendaring, contacts and tasks; support for mobile and web-based access to information; and support for data storage.

Axigen is a premium, all-in-one email, calendaring and collaboration platform, based on an innovative, proprietary technology, providing unmatched manageability for system administrators. Integrating all modules in a robust messaging solution, Axigen is developed for demanding users, from small businesses to large service providers.

Kopano puts an email, video meetings, calendaring, and file sharing solution within one single interface.

Open Source Collaboration, providing integration with your existing Linux mailserver, native mobile phone support, Outlook "Look & Feel" webaccess and stable Outlook sharing (100% MAPI).

MDaemon Messaging Server software for Windows can be deployed in virtual, hosted cloud or private on-premise environments. It is used by businesses in over 90 countries and over 25 languages worldwide.

hMailServer is a free e-mail server for Microsoft Windows. Its used by Internet service providers, companies, governments, schools and enthusiasts in all parts of the world.

At the core of IceWarp's messaging platform is a scalable and robust SMTP/IMAP/POP3 server capable of handling 1000's of messages per minute in multiple outgoing queues. All services are secured with SSL/TLS encryption, supporting deployment of any kind, from mail relays, integration to websites, up to load-balanced platforms and geographically dispersed architectures.

OBM is a free messaging and collaboration platform useful for just a couple to many thousands of users with strong support for mobile devices.

The Mercury Mail Transport System is a mail server that sends and receives messages on behalf of a group of users on a machine or local area network. Messages from the outside world are received by Mercury and delivered to the users, who can access it at any later point. Messages sent by local users to the outside world are passed to Mercury, which then takes whatever steps are necessary to deliver them, removing the burden from the users workstation and allowing them to continue with other work. »

Full featured solution for your Email server. Native implementation of last anti-SPAM metods, webmail and easy administration included.

Turnkey Solutions for the Enterprise Cloud

Atmail allows you to choose between on-premises or cloud deployment. Features include email, contact, calendar, task, storage, synchronisation and provisioning.It's extensible through a RESTful API and allows easy rebranding and white-labelling.