"You should not run your mail server because mail is hard."
"TL;DR: - Mail is not hard: people keep repeating that because they read it, not because they tried it - Big Mailer Corps are quite happy with that myth, it keeps their userbase growing - Big Mailer Corps control a large percentage of the e-mail address space which is good for none of us - It's ok that people have their e-mails hosted at Big Mailer Corps as long as there's enough people outside too"
Bollocks. I did try it. Twice. It is hard and best left to the professionals.
Of course, if you're just a hobbyist email user, go right ahead. If you use it for any serious purpose, pay money to someone who knows what they're doing.
I'm not the author of this article, but I think that their intended readers are persons who are already into selfhosting but may have left aside email server maintenance because of the relatively bad reputation it has. By writing in a polemical way, it seems they want to simply convince these admins to just give it a try by themselves (and sneak in a bit of publicity for their own software, but that's fair enough). I think this is definitively worth it.
Having run a few small email servers for more than 15 years now, as an amateur sysadmin doing this as an ideologically motivated hobby, I can say that: 1. don't do it alone, find other people to co-admin a box with you and limit your users to friends/family/collective; 2. Email is hard to reduce to one specific software or stack, it's highly modular and has a lot of moving parts, this can be confusing as no HOWTOS will look the same as a result; 3. the real challenge is that the configuration is stretched through time, you have to acquire the lingo and do a couple of things in the first run to tune it right, and it takes time to test all and see the effect of different settings as it's not all easily testable on your own (although these days you have services that allows you to give useful feedback like mailchecker and others); 4. once you have something stable, a simple setup is almost "set and forget", and only rarely will you need to update things to take into account the latest email novelty.
Of course YMMV!
@320x200 What do you do for spam filtering? I find that’s one thing Google does really well, to the point where even Apple iCloud can’t compete.
@acb on one machine that receives a lot of crap because it hosts several discussion lists I use these settings: https://things.bleu255.com/runyourown/Backscatter_Rejection and https://things.bleu255.com/runyourown/Greylisting
On another one that somehow never gets too much spam even though it's a very active server for several years, we don't do anything besides known tricks like dropping any incoming emails that are not sent correctly (spoofing, weird commands or source, etc) and that's enough. We get a few that pass through but that's not a big issue. If it gets worse we'll use greylisting.