It's a great idea except that for one person it's going to cost a lot more than buying an account on FastMail (disclaimer: I work there) or any of the other hosting sites (even before you start start thinking redundancy and backups - we have about 10Tb of disk for every 1Tb of pure email quota, by the time you count search indexes and RAID and 3x replication redundancy - two local one offsite) For more than one perso…
Fastmail costs $40/yr. You can get a half-decent VPS for that with a few bucks to spare on Tarsnap.
You also must buy an ssl cert or else many other email providers will mark your email spam score up.
You also must go through the operational burdon of setting things up and managing backups, restores, etc. This is perhaps 30 hours / year, which means you're already well over the cost of $40/yr.
One thing to note is that for more than a few accounts (bring your own address, catchall, many aliases) you're unlikely to find something that costs as little as $40/year and the cost of running that yourself is identical, so that's where you can start to make money.
I've gone down the route of using hosted and hosting my own mail and feel like I have a good understanding of the costs.
Your flippant remark, completely disregarding even the system requirements, shows that you have not. Good day sir.