The 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, calendaring, and mailing list services.
The first Open-Source high-performance MTA for high-volume senders
KumoMTA is an Open-Source, enterprise-grade email message transfer agent (MTA) software for sending high-volume, business-critical emails. KumoMTA is typically chosen by high-volume email users looking to replace PowerMTA, Momentum, or traditional Open Source MTAs.
KumoMTA offers high-performance message relay to the tune of millions of messages per hour per server, combined with extreme flexibility and configurability through its use of a Lua scripting engine for configuration and...