Mailchimp Project Omnivore: Declassified
blog.mailchimp.com
blog.mailchimp.com
Besides, I just want a clean inbox. I don't care whether a given piece of trash came from a commercial or non-commercial source.
(Besides, if you don't want any unsolicited emails, it's pretty trivial to blacklist everyone and then manually add exceptions after you've agreed in advance to allow someone to email you. ISPs and such don't need to get involved in that, so they don't need to worry about it.)