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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NetUSB 

NetUSB is a powerful, fast, and easy-to-use email experimental tool.
netusb

Email2DB 

Email2DB is an email parser and auto responder. It parses email messages and extracts field data to update back end databases and send auto-responses. Email2DB is ideal for any form-based emails such as orders, customer accounts etc.
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AD MailBox Manager 

AD MailBox Manager allows you to browse your mailbox and view subject, sender, receiver and size of incoming messages prior to downloading them. Also, you can delete messages direct on server. Support multiple accounts and new messages notification.
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FTGate 

FTGate4 is a powerful Windows mail server with comprehensive Groupware functionality. Features include calendaring, contacts, IMAP, anti-spam , anti-virus support, multiple domains, Web Administration, WebMail, instant messaging, SPF,SSL + more.
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CliMail 

CliMail is a set of command line utilities designed to send and receive email. Send plain-text or HTML (with embedded pictures) email with attachments using to, bcc, and cc recipients. List, display or delete email from POP3(S) or IMAP(S) mailboxes
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