LDAPManager is a free Windows LDAP Editor/Browser with many advanced features such as batch editing and server to server copy.

Fully-featured SMTP/POP3 mail server program with a range of security features and options to use along with any mail client as a personal local SMTP server or as a stand-alone mail server. It works in the logoff mode; SMTP gateways are supported.

Anti-spam protection and message tracking for SMTP servers

1st Up Mail Server is a simple to configure yet powerful mail server that has been specifically designed for the small to medium sized network.

A server and client tool with database support and a C library to create your own B to B applications.

MailFender for Exchange protects your Exchange Server from spam and viruses. It provides you with powerful rules for defining email policy, legal/commercial disclaimers, attachment removal and detection of inappropriate language.

SMTP server program for Windows that lets you send email messages directly from your computer. Along with a mass mailer the program can be used as a relay server for sending newsletters, distributing messages to different mailing lists

NaviCOPA takes the hard work out of running a Web Server. The NaviCOPA Web Server installs on any version of the Microsoft Windows operating system with just a few clicks of the mouse and automatically configures itself for instant HTTP access.