MailEnable Enterprise is a powerful mail server for Windows 2000/NT/XP. It supports SMTP and POP3, supports an unlimited amount of email addresses, domains, groups and mailing lists. Enterprise Edition incorporates Web Mail, HTTPMail, IMAP4, Personal calendars, Message Filtering, Web Administration (including remote admin), Anti-Spam including Bayesian Filtering and support for third party Anti-Virus software. Easy to install and configure.
