The Email Server 

The Email Server is a Microsoft Windows-based SMTP and POP3 server
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GroupWare 

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 Exchange.
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MailEnable Enterprise Edition 

MailEnable Enterprise Edition is designed for organisations or ISP's dealing with high volumes of mail, requiring greater control and flexibility over mail services.
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MailEnable Professional 

MailEnable Professional Edition is a enterprise level mail server for Windows 2000/NT/XP. It supports SMTP and POP3, supports an unlimited amount of email addresses, domains, groups and mailing lists.
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MailEnable Standard 

MailEnable Standard provides robust SMTP and POP3 services for Windows NT/2000/XP/2003 systems. Simple installation procedure and powerful administration tools means that you will be up and running quickly. FREE for personal and commercial use.
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1PopCheck 

Retrieves emails from any standard POP3 server. Allows viewing, deleting and defining rules on emails along with many other administrative features. Emails from various accounts can be checked in a single window. Costs $9.99.
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