Kopano!

Kolab is entirely Free and Open Source Software (a.k.a. FOSS), and uses Open Standards. We’ll get to why this is important to us, and hope that it is important to you thereafter.

Kolab Now, formerly MyKolab, is a fully featured secure collaboration and communication service that is easy to use on any device.

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.

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.

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.

Kerio Connect makes email, calendars, contacts and task management easy and affordable. With Kerio Connect, you have immediate, secure access to your communications anytime, anywhere, on any device - without complexity or expensive overhead.

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.

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. »

Atmail webmail system offers a webmail client, email server platform and mailserver appliance for Linux, Unix and Windows.

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.

OpenChange aims to provide a portable Open Source implementation of Microsoft Exchange Server and Exchange protocols.