To all the folks answering basically "yes it's hard" I think the headline is a bit clickbaity but there are some interesting takeaways... To summarize, (a) yes it's harder than setting up Big Corp Mail, but (b) a lot of the horror stories are either old or secondhand, and (c) it's a lot less hard to set up than it used to be.
If the suggestion is, why not give it a try, one thing I feel is missed is, how hard is it not just to set up but to run over the long run, when the technology evolves and you have to keep up, and why would any IT manager or CIO want to gamble their careers on this?
Exactly. I'm curious too. It seems like the author has something up their sleeves -- OpenSMTPD, apparently. But when I look at the homepage[0], I see a very typical linux-y man-page-style homepage... A far cry from what I would consider simple.
There are a bunch of guides floating online for Postfix, Dovecot etc, and some of them are pretty decent. But they go out of date quickly, or if you want to do something slightly different, you're on your own... And even if you end up with a running system, maintaining or enhancing it is a different kettle of fish. You can't just follow the guide again, you're back to man pages and usenet mailing lists with some info inside a thread 23 levels deep.
On redhat derived systems, setting up a basic mailserver was never harder (post 2010) than service "sendmail start & & service dovecot start" + adding a couple of DNS records. Not knowing this means not having done one's homework. Which is also a good indication that one should not be messing with email.
And knowing it is still being long way from running an effective mail server.
If the suggestion is, why not give it a try, one thing I feel is missed is, how hard is it not just to set up but to run over the long run, when the technology evolves and you have to keep up, and why would any IT manager or CIO want to gamble their careers on this?