IndiMail is a messaging platform built using qmail and other messaging software. IndiMail has the ability to distribute the users in a domain across multiple hosts. IndiMail has multiple queues (called a queue collection), which can achiever very high concurrencies. The system IDs and configuration files used by IndiMail are all configurable through a set of environment variables, allowing you to customize IndiMail the way you want. IndiMail does not use hard-coded uid/gid in the executables, which makes it easy to distribute a binary package. IndiMail has features that any modern email server should have: SMTP, QMQP, QMTP, IMAP, POP3, DKIM, BATV, greylisting, filtering capability, and spam/virus control.
Korallenriff is a program that collects input from different network sources and stores their data into one database. For example, it can receive POP3 mail or can fetch NNTP groups and store the received messages in a database. One can then, for example, use the database data within a Web site to display the latest postings of a newsgroup or to create an online mailing list archive. Another possible use would be to build a blogging-software where one can post via email.