IndiMail is a mailing solution built using following packages qmail, serialmail, qmailanalog, dotforward, fastforward, mess822, daemontools, ucspi-tcp, Courier IMAP/POP3, Bogofilter - A Bayesian Spam Filter, Fetchmail, other useful utilities (pack, unpack, altermime, ripmime, fortune,  flash). IndiMail also provides Management of Virtual domains. Lot of the integration has been done by modifying some of the core components. You can read the feature list to get an idea of the changes and new features that have been added over the original packages.

IndiMail also provides Management of Virtual domains. Lot of the integration has been done by modifying some of the core components. You can read the feature list to get an idea of the changes and new features that have been added over the original packages.

As a hobby way back in 2001, I started playing with qmail. Over the years, i learnt how to use qmail and put together a complete solution which worked quite well for me and can work for large ISP installations (> 8 million+ users in a single domain across multiple hosts and more than 4 million deliveries per day). Maybe some of the stuff could prove useful for someone who had the same situation as me (very little budget to buy costly NAS filers, availability of simple hardware, etc).

The package combines qmail with other packages like courier-imap for IMAP/POP3, bogofilter for SPAM control, fetchmail for hosts with intermittent connectivity. IndiMail provides ability for a single domain to have users across multiple hosts (even across different geographical locations) and tools to manage virtual domains ?

This package also allows me to split my users in a single domain across multiple hosts without using NFS. I haven't looked at qmail-ldap but maybe this package does something like qmail-ldap but with MySQL as the backend for storing user information. The tools for administering virtual domains/users will have a lot in similarity to the vpopmail package from inter7.com. The table structures are the same. Plenty of code (for managing virtual domains/users) has been borrowed from there. Since the user get split across multiple hosts, IndiMail also provides two proxies for IMAP & POP3 protocol. The proxy servers run using daemontools and are by default set under supervise. You can use any IMAP/POP3 server behind the proxy. IndiMail also allows you to add any proprietary mail server serving some of the users of any domain which you want to configure under indimail. This makes it easy to migrate from an existing proprietary mail server like MS Exchange in 5 steps.

The Steps are

1.You simply set up a new installation with IndiMail with the existing domain

2.Add the IP address of the Exchange Server in host_table and the SMTP port of the Exchange Server in the table
  smtp_port
3.Add users on the exchange server to a table called hostcntrl (either manually or using the utility hostcntrl).
4.Set up SMTP, IMAP Proxy, POP3 Proxy on the IndiMail server
5.Change the MX to point to the IndiMail server