I am running my server for 15 years and couldn't be more happy with "artisan" infrastructure.
I don't want or use webmail (sluggish), I don't want others fingerpoking my emails, I don't want various compulsory registration systems (like requiring my phone number out of """security""" reasons like google), giving others the ability to kill my account and do me a huge amount of work and on the top of that, it breaks the sites registration schemes, I have set up a script that accepts any email with some special structure and each and every registration gets a specially customized mail address (that I can calculate in my head, no configuration needed) that can be resolved back to the registration.
Getting spam? I am sick of you, whatever? No issue, just REJECT the whole address. It is used by only one site, like smart people don't reuse passwords, I don't reuse email addresses.
And you would be surprised, how many sites sell email addresses to others, and I know it as every one gets its own email address.
Rspamd eats the spam just as good as "ai infrastructure" /s
Even if you go for 3rd party email infrastructure, registering a domain is a must, so you can switch the provider fast if it gets vampirized.
Out of my whole infrastructure (100% self hosted, as said, for 15 years, actually more but not 100%), the email server is the part that needs the least attention.
The response to the author would be: nice that large providers have webmails and some other quirks that I don't want or need. Feel free to use them, but I have freedom.
postfix. dovecot. rspamd.