A highly scalable/configurable Mail platform allowing users in a domain to be distributed across multiple hosts, has multiple queues and uses qmail as MTA.
Also provides virtual domains/users in MySQL. No patching of qmail required. A full-featured mail server providing ESMTP, IMAP/POP3, QMTP
... [More], QMQP, DKIM, DomainKeys, etc
In tests carried out by users, IndiMail's multi-queue architecture outperforms postfix in mail inject rates.
IndiMail allows extending a domain across multiple servers. This feature also allows you to setup a domain with a heterogeneous mix of mail servers.
Read more about IndiMail at
Rumble is a mail server suite for SMTP (ESMTPSA), HTTP, POP3 and IMAP4v1 with an extensive C/C++ and Lua API for scripting. It comes with support for SSL/TLS, SQLite and MySQL and has a web-based administration and webmail feature. Additional included modules feature greylisting, DNS blacklisting
... [More], SpamAssassin support and dynamic performance scaling as well as a multithreaded structure that allows for clustering of multiple servers for one or all domains, and with the ease of the Lua API, you can create your own new server mailing lists, CRM software, e-marketing and other extensions within minutes.
Rumble Mail Server Web Site [Less]