I think DKIM was a good idea at the time of its inception. It caught a lot of the low hanging fruit, which was spammers who spoofed domains.

But yeah, now anyone can buy a domain for dirt cheap, setup DKIM, and start spamming away.

At least with DKIM, you have a basis for blocking a domain outright. That is, until they buy up another domain and repeat their spamming activities again.

Email has really fallen apart in the past decade. When it's not spam, it's retailers and other companies sending me unsolicited, unwanted marketing emails, entirely without my consent. They are the bulk of the garbage in my inbox today.

It's amazing to think that companies still think this is a valid way to advertise products and services. At best, people get annoyed and dump you in the Junk folder. At worst, they view it as a form of begging by a desperate company looking for money, and those people definitely won't be interested in buying anything from you ever again. If there was a way to measure it, I would be that companies are losing more money from annoying spam marketing campaigns than from the .00001% that do convert.

Mailchimp, Constant Contact and their ilk are truly a scourge upon our inboxes. You know they're truly terrible companies because if they ever provided a global opt-out of all their email lists from all their clients, they'd go out of business.

One of these days I will just create another self-hosted email service of my own with a fresh domain and only whitelist it with recipients that I actually care to hear from.