ListServe Pro 

ListServe Pro is a program that enables NewsLetter capabilities on a website when there is little more than disk space and an email account available from your ISP. No CGI!
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Advanced Maillist Manager 

Advanced Maillist Manager (AMM) is designed to process incoming messages that contain subscribe/unsubscribe/etc requests.
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netMailshar 

netMailshar is an easy-to-use, powerful mail server that enables every computer in an office to send and receive email not only across the Internet but also within a LAN. It provides centralized, generic protection against all email viruses.
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Winsock Interface Library for C/C++ 

The Winsock Interface Library simplifies winsock network communications programming and provides support for the most common Internet protocols such as Finger, SMTP, POP3, FTP, NNTP, and HTTP. Includes multiple C/C++ examples.
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