>On a side rant, I really dislike how a lot of websites have normalized “create an account on a website” to mean “Sign up for receiving a plethora of emails about everything the website and its creators are up to these days”

Hear, hear. If I get an email from a company whose newsletter I didn't sign up for, I immediately unsubscribe... but I really shouldn't have to.

One of the greatest parts about owning my own domain is using different email addresses for these random websites that want to blast me with newsletters. That way, I can just redirect [email protected] to the trash if they sold my email address or I start getting spam to that address.

You can do the same thing in Gmail with the +, but some websites filter those out or don't allow them.

What websites have you had issues with? I started doing the same thing with my own domain about a year ago, but I haven’t see any unsolicited emails to any of the addresses yet.

I was expecting you to say "I immediately mark it as spam". Do it, treat unsolicited newsletters like the spam they are. If enough people do this, it creates significant problems for the authors of such email.

I do that. Just unwanted = unsubscribe; unexpected = spam; if unsubscribe link doesn't work or requires logging in => spam.