Re: Me feeling happy ...
"I do that as well - for the instances where they, reasonably, do need an email address. Running my own MTA means"
Well, technically, I do run my own MTA. The fact that almost all the email that I *WANT* to receive ends up in a bog-standard commercial webmail account is neither here nor there (and anything addressed direct to that account only that didn't come from my MTA? Spam).
The fact is that I can switch it out any time I like to ANY destination, I can give people addresses (e.g. myfriend@mydomain.com, which forwards to his weird ISP-specific email), and I can filter at a level above what those providers do (e.g. all my email is greylisted for 5 minutes, etc. all the "misused" addresses go straight to the bin, and I can do tricks like "this is a valid email because it fits my rules on how many vowels each of my emails should have / what the number in the email should checksum to" so that even being able to make up emails doesn't give OTHER PEOPLE the ability to just make them up and spam me - I get a surprising amount of usernameusername@mydomain.com and even partial /corrupted usernames where the database obviously didn't line up correctly in their mailshot).
But once set up, the personal effect is "log into my normal webmail, have no spam, can tell if an email was GENUINELY from paypal in seconds because only paypal know what the paypal address they have this year actually is".