Couriers

Courier mail transfer agent (MTA) is an integrated mail/groupware server based on open commodity protocols, such as ESMTP, IMAP, POP3, LDAP, SSL, and HTTP. Courier provides ESMTP, IMAP, POP3, webmail, and mailing list services within a single, consistent, framework. Individual components can be... Platforms: *nix

Courier-IMAP is a fast, scalable, enterprise IMAP server that uses Maildirs. Many E-mail service providers use Courier-IMAP to easy handle hundreds of thousands of mail accounts. With the built-in IMAP and POP3 aggregation proxy in Courier-IMAP 4.0, the only practical limit to Couriers... Platforms: *nix