//" install a Debian machine, and do:
aptitude install postfix
aptitude install postgrey
install either a webmail (roundcube most commonly), or go to (http://www.postfix.org/docs.html). If a spam gets through, install blacklisting or spamassassin.//
You seriously think this is simple for non IT people?
No, I don't think this is simple for non IT people. Same goes for my web site code, or my python projects, or my shell scripts. If I gave either of those to an non IT person, they would have no clue what is going on.
This is as expected, as most people require some expertise to do technical work. I would have no idea how to fix the electrical system in a car, but I do expect that the mechanic knows how to figure it out if it one broke. Same, I expect a sysadmin or a programmer has the expertise to follow single steps installation guides.
You seriously think this is simple for non IT people?