To provide some details that might not be immediately obvious, this is a piece of software that takes care of installing and setting up the various pieces one would use to run (in my opinion) the ideal mail system: Postfix, Dovecot, MySQL/PostgreSQL, OpenLDAP, spam filtering, webmail, etc.
All of the software is, of course, open-source/free software but the iRedMail-Pro "management" application is what you are paying for (there is also a free version w/ less features). You can certainly implement everything yourself from scratch without paying for it.
I'm not a customer and have not used it although I did look into it a while back. The few people I asked who had used it were satisfied with what they received for the price. YMMV.
Note: someone claiming to be the developer of this project left a comment on this thread, but has a new account apparently spam: his comment is dead. (Always browse with showdead turned on.)
All of the software is, of course, open-source/free software but the iRedMail-Pro "management" application is what you are paying for (there is also a free version w/ less features). You can certainly implement everything yourself from scratch without paying for it.
I'm not a customer and have not used it although I did look into it a while back. The few people I asked who had used it were satisfied with what they received for the price. YMMV.