How is infinitely more expensive than free affordable? And how is it good that it is non-trivial to run your own mail server?
Companies that provide these services have to spend countless hours stopping spammers using their services to send mail. But they do it for your benefit, despite the small costs.
Sending email is cheap, and any reasonable business is probably having sending email as one of its lowest costs. We really should be grateful to most of these companies to work so hard on our behalf to keep it that way.
And what about individuals?
> We really should be grateful to most of these companies to work so hard on our behalf to keep it that way.
I don't think so. They are also keeping it hard to run your own mail server. Plus, they get to have access to tons of other people's emails, which is a terrible idea. What's the point of introducing SMTP-STS when you then create some few central entities that hold all the keys?