Why would you use FastMail when hosting your own mail server has a much higher privacy level? It seems no better than gmail in this respect.
FastMail is a cheap and easy option to email. They provide some services that I value over what free accounts have. It is a compromise, but everything is. I freely admit that I was failing at administering my own email servers: I never did get some anti-spam thing in place so a few domains rejected everything I sent. I got about 100 spam messages in my inbox every day (my filters caught 3 for each they let through). With Fastmail everyone accepts my email, and I get about one spam message a week which I can handle.
So is spinning up a docker container with this all already configured... I just don't see the argument I guess, it's just too easy to do yourself. Instead you're getting ripped off and losing privacy. There's no reason to believe fastmail is any more private than GMail, staff can just as easily read and deliver your mail to whomever they please.
A medical degree takes years to get, this takes 10 minutes for a basic setup, an hour or two for a more advanced one, assuming you're in the industry already and know your way around.
Rebuilding your docker when you hear about that is not exactly something I'd consider a big deal, but I guess if 2 minutes work every 3 years is worth giving away your privacy, then you do that.
Backup is a set and forget cron job (tarsnap mail dir), so I don't see how that's an issue.
Again, Docker isn't magic.
As for the rest those aren't really issues you need to actively watch, you'll just know when something goes wrong to take a look. I can't see running out of disk with just a mail service, crashes are... never and compromise/DDoS isn't really a risk if you secure it properly to begin with and update it that once every few years. It's really very hands off if you're not running any other services and just review the vulnerabilities.
I'm guessing this is even less of a problem for most of us though because I and probably many others around here already run a personal dev server which is kept up to date regularly, so I was speaking simply to adding mail functionality to an existing system previously.
Oh yeah, me too, and tbh it's enough of a pain already without having to deal with mail, spam and the likes.
There is a reason that companies like Heroku exist and prosper; it's the same reason personal mail servers never saw mass-adoption, despite being one of the first things you could do on the internet. The anecdote that you find it easier than most doesn't change the reality of the matter.
Maybe if someone made an integrated mail server it'd be more common.
It's a pain in the ass from time to time, especially if you don't administer Linux boxes for a living. I've been running my own MTA for well over a decade, and have dealt with every one of the issues cited by the other people responding to you in this thread, as well as most cited by other people discussing this article in general, and a few (such as the advent of deliverability/spam-fighting tools like DKIM and DMARC) which I haven't seen anyone else mention. I haven't kept close track, but I'd say it's cost me altogether somewhere between one and two weeks of time over the years - and that doesn't count initial setup, because I did that back before you could just pick any of a dozen HOWTOs that'd take you through the whole process end-to-end.
For me, and apparently also for you, that tradeoff is worthwhile. (For me, not least because the amount of effort required has gone nearly to zero in the past few years. If that weren't true, I'm not sure I'd feel the same way.) For a lot of people, that tradeoff makes less sense than spending about the same, or a bit more, money, in order to have their mail infrastructure looked after by professionals who do it for a living. Granted, they have to deal with risks that we don't, like Google's habit of surprising its users with rather stupid UI changes, only some of which fail to last. But we have to deal with risks that they don't, too. We prefer control to convenience and are willing to spend time and effort to get the result we want, and that's okay. Others prefer convenience to control and would rather spend money to get the result they want, and that's okay, too. Different people have different needs.
If that's still confusing, I don't really know what to tell you. Sorry.
If you are willing to deal with the occasional hiccup and learn about the odd issue as it comes up, the above is not really a huge concern. But if you are like me and would give up a lot to avoid the horror of realizing some email(s) have not gone through at the worst possible time (i.e. on the day of an important business deadline, with no time to troubleshoot the root cause), entrusting your mail to a platform like Google or FastMail is a must.
The "tinkerer" aspect of me would like to run my own mail server and would enjoy knowing that it's fully within my control and configured exactly the way I want it. The pragmatist in me says, "No way!"
That, and all the complications that running your own email server brings with it. If you read the article, the author explains it very well.
I have to disagree, it sounds like he just had a crappy provider, avoiding blacklists is pretty much just a matter of having your RDNS, SPF and domainkeys configured properly in my experience. Pretty trivial stuff, really.
At the end of the day, email IS NOT secure. If you're paying for a service and they can say they're not reading your emails and they will respect your privacy, well that's good enough for me.
These are just some of the reasons.
Configuration (at least using dovecot and postfix) is easy too once you get started.