Messaging Application Programming Interface (MAPI) is an API for Microsoft Windows which allows programs to become email-aware. While MAPI is designed to be independent of the protocol, it is usually used to communicate with Microsoft Exchange Server.
SOGo is an open source collaborative software (groupware) server with a focus on simplicity and scalability.
Open-Xchange is a web-based communication, collaboration and office productivity software suite, which enables full integration of email, documents, scheduling and social media.
Kontact is a personal information manager and groupware software suite developed by KDE. It supports calendars, contacts, notes, to-do lists, news, and email. It offers a number of inter-changeable graphical UIs all built on top of a common core.
Calendaring Extensions to WebDAV, or CalDAV, is an Internet standard allowing a client to access scheduling information on a remote server. It extends WebDAV specification and uses iCalendar format for the data. The access protocol is defined by RFC 4791. It allows multiple client access to the same information, thus allowing cooperative planning and information sharing. Many server and client applications support the protocol. Extensions to CalDAV for automated scheduling are also standardized as RFC 6638.
Scalix is an e-mail and groupware server that runs on Linux, licensed under the Scalix Public License (SPL).
Zimbra Collaboration, formerly known as the Zimbra Collaboration Suite (ZCS) before 2019, is a collaborative software suite that includes an email server and a web client.
Group-Office is a PHP based dual license commercial/open source groupware and CRM and DMS product developed by the Dutch company Intermesh. The open source version, Group-Office Community, is licensed under the AGPL, and is available via SourceForge. GroupOffice Professional is a commercial product and offers additionally mobile synchronisation, project management and time tracking.
Bynari is a company based in Dallas, developing server and email software, mainly known for its Insight Family, similar to Microsoft Exchange Server with Outlook.
Axigen is a Linux, Windows, and Docker mail server with groupware and collaboration functionalities. It supports SMTP, IMAP, POP3, and webmail services, and includes features such as an integrated mailing list server, Antivirus and Antispam integration options, and various mobile capabilities including mobile-friendly webmail and Exchange ActiveSync support. Axigen can be hosted in data centers, on bare-metal or Private or Public Clouds of choice.
Zarafa was an open-source groupware application that originated in the city of Delft in the Netherlands. The company that developed Zarafa, previously known as Connectux, is also called Zarafa. The Zarafa groupware provided email storage on the server side and offered its own Ajax-based mail client called WebAccess and a HTML5-based, WebApp. Advanced features were available in commercially supported versions. Zarafa has been superseded by Kopano.
GroupWise is a messaging and collaboration platform from Micro Focus that supports email, calendaring, personal information management, instant messaging, and document management. The GroupWise platform consists of desktop client software, which is available for Windows, Mac OS X, and Linux, and the server software, which is supported on Windows Server and Linux.
IceWarp, Inc. is a software company located in Springfield, VA developing IceWarp Mail Server, an email, messaging and collaboration service for small, medium and enterprise level businesses. IceWarp has offices in the United States, Germany, Russia, Czech Republic and India. The company has been in business since 1998 and is used by over 50,000 businesses around the world. Its product is alternative to Exchange Server, Office 365 or G Suite.
Kolab Now is a web-based email and groupware service, based completely on free and open-source software. It is owned and operated by Kolab Systems AG and was formerly known as MyKolab.
Zentyal is an open source email and groupware solution based on Ubuntu Linux.
MailEnable is a Windows-based, commercial email server distributed by MailEnable Pty. Ltd, an Australian-based software company which was established in 2002.
Kopano is an open-source groupware application suite originally based on Zarafa. The initial version of Kopano Core (KC) was forked from the then-current release of the Zarafa Collaboration Platform, and superseded ZCP in terms of lineage as ZCP switched to maintenance mode with patches flowing from KC. Kopano WebApp similarly descended from Zarafa WebApp. Since October 2017, Kopano Core is also known more specifically as Kopano Groupware Core, since Kopano B.V. developed more products that were not directly requiring groupware components.
MDaemon Email Server is an email server application with groupware functions for Microsoft Windows, first released by Alt-N Technologies in 1996.
