> For users who don't pay for their personal email, email is nothing but a marketing channel and a very inefficient one at that.
I have a paid personal email plan on my own domain name. (Mostly to get aliases and plus addresses). It is setup very well and filters spam very efficiently, compared to some 'corporate-standard' filters on other services. But I still have to use my gmail address because most individual contacts wouldn't see my mails otherwise since they are on gmail, hotmail, etc. And for many official websites, my email addresses are 'not valid email addresses'. Granted that my TLD .space isn't an official sounding one, but it's used by exactly two types of users - people who use it as their space, and people/organizations working on space tech. So I pay, but I'm still forced to watch them spam. Honestly, I believe that email is now a captured monopoly (cartelopoly?).
> I would love to see a more secure protocol to replace it, where the recipient always has full control over all the messages that he can ever receive.
I wholeheartedly agree. Email is an awesome idea. But its age is starting to show. We need something with security and encryption built-in, much fewer moving parts (Can we integrate MTA, MDA, WebUI, spam filters, DKIM, etc into just one?), option to opt out of rich formatting (the HTML and AMP junk), dynamic updates, etc and proper spam filtering, etc. We should also have a way to disincentivize or punish big players from rejecting valid emails. Perhaps it can use HTTPS to overcome those pesky corporate reverse proxies and firewalls.
But the idea of having a domain name as a namespace for users is still precious.