• High performance SMTP mail server
• Enterprise IMAP server that uses Maildirs
• Integrated content scanning (ClamAV and SpamAssassin)
• SMTP Authentication from MySQL
• Supports from few to hundreds of thousands of mail accounts
• POP3 support
• Unlimited Virtual Domains
• SSL/TLS
• Web-based administration (demo)
• Per User/Account Quota
• All account info stored in MySQL (No system user required)
• Support for Web-based e-mail (Squirrell Mail or SqWebMail)
• Full mailing list server support (Mailman)

Download and install ECM2

All versions of ECM previous to ECM2 are now considered obsolete and everyone is strongly recommended to switch to ECM2.

For reference here are the links to the archived pages.

ECM for Tiger (prior to ECM2)

ECM for Panther

ECM for Jaguar