GroupWare   
http://www.altn.com

MDaemon GroupWare unlocks the collaborative functions of Microsoft Outlook using MDaemon as the mail server platform. Outlook users can share Calendar, Tasks, Contacts, Notes, and Journal folders without the expense or expertise required by Microsoft Exchange Server. Features include user configurable permissions where GroupWare users has control over the permissions of which folder(s) they wish to share with other users, WorldClient (MDaemon's web-based email client) will allow you to see items in your Outlook calendar from anywhere, and GroupWare licensing is independent of your MDaemon license size.

MDaemon   
http://www.altn.com

MDaemon , Windows-based email server software, contains full mail server functionality and control with a strong emphasis on security to protect your email communication needs. MDaemon features include top-notch antispam security features; seamless integration with AntiVirus for MDaemon plug-in; built-in groupware functionalities for sharing folders, tasks, contacts, and address; separately licensed plug-in for Outlook users to access groupware functionalities using MDaemon as the mail server and groupware platform; secure instant messaging; free web-based email client; remote administration tool; central address book repository; and much more! MDaemon 8.1 new feature includes the first implementation of DomainKeys Identified Mail (DKIM) for the Microsoft Windows platform. DKIM validates the sender address and message integrity of each email received. MDaemon creates outbound signatures and validates inbound messages signed with DKIM. Read Alt-N's published white paper on DKIM and its implementation in MDaemon at http://www.altn.com/support/white_papers.asp. In addition to DKIM, MDaemon 8.1 includes support for Greylisting, a relatively new spam fighting technique which involves deferring the initial acceptance of a new mail message from unknown senders and tells the sending email server to try again later. When the sending server tries a second time - which most spam sources will not do - MDaemon will accept it. Exception options and white lists can exempt trusted senders from greylist processing. MDaemon 8.1 builds on the groupware, security and administrative improvements made available with MDaemon 8.0. MDaemon now includes free groupware functions, including shared calendars, contacts and task lists. It also continues to lead the industry in email security, professional fine-tuning and beginner ease of use.

CARTHAGO Groupware   
http://www.atrium-software.com

CARTHAGO Groupware 2005 is a application server for MS Windows platforms to manage email, contacts, groups, appointments and tasks using a standard web browser. Through a regular webserver, you have access to your personal data from everywhere in the worldwide internet. All data is stored in a SQL database and is available very fast. Each user has his personal address book and appointment calendar. Existing MS Outlook or Outlook Express contacts can be imported easily with the build-in import feature. Special groupware features allow multiple users inside the domain to share contacts and appointments. Received messages can be clearly arranged with message folders. Each user can decide from which originators he wants to receive messages using his personal anti spam list. A build-in auto responder responds to incoming messages with predefined text templates. CARTHAGO supports international domain names (IDN) and is thus also suitable for email addresses with special characters, without the need of a special conversion tool. Layout and language of the user interface can selected by each user himself. System administrators can change server settings, edit domain and user accounts and view active sessions using the web based configuration menu. A detailed event log shows information about all user activities. CARTHAGO Groupware 2005 contains a ISAPI interface and can be integrated in almost every webserver with ISAPI support. The open database interface allows the usage of different kinds of database systems to store the data.

FTGate   
http://www.ftgate.com

FTGate4 is a powerful Windows mail server suite that combines exceptional mail handling facilities with comprehensive Groupware functionality. This fully featured and highly secure POP3/SMTP server suite is suitable for Win NT/2000/XP/2003 The new groupware corporate/personal information manager Solsight within FTGate4 gives full groupware access without the need for expensive Microsoft(TM) products. You can now have groupware with your favourite mail client. Features Include: Enhanced mail server functionality, Web Administration, Web Mail (English/German), SolSight PIM/CIM, Groupware Client, Shared Folders, (IMAP and WebMail), Shared Contacts , Shared Calendars , Shared Task lists, Instant Messaging, Instant Popups, Instant Notifications, Powerful Anti-spam, Anti-Virus support, Enhanced Security, Encryption (SSL/TLS), Free Migration Tool, Multiple domains, Mailing lists, POP3, LDAP, SPF (Sender Policy Framework), and much more.

Merak Mail Server Suite   
http://www.icewarp.com

Multiple awards winner mail server with ultimate features, complete security and guaranteed stability. Provides a wide range of optional components and services including secured mail services with multiple domain support(SMTP, POP3, IMAP), user-friendly Web-Mail (Outlook-like interface), Anti-Spam with updates (SpamAssassin, SPF, Bayes, SURBL, ChallengeResponse, DomainKeys, Greylisting), Anti-Virus with updates, Instant Messaging (based on the Jabber XMPP protocol, also accessiale via web, supporting AOL, ICQ, MSN, Yahoo and other Jabber and Merak servers), GroupWare (accessible via web and Outlook), FTP (secure FTP server with many features and the system integration), load balancing (ODBC support), monitoring and report facilities (charts and reports), developers API, several account types (mailing lists, list servers, executables, catalogs, static routes, remote accounts, users, domains), system alert tools, remote administration and many other features and tools. Merak mail server suite is a reliable, easy to use, and affordable communication solution that is used by more than 40 million users worldwide. Available on Windows and Unix based systems.