[ubermonkey]

Mailgun is a spammer, so, like, cry me a river?

I have them blocked at the server level because of how much spam they were sending me. They clearly do zero enforcement of opt-in.

[jdhawk]

how are they supposed to enforce it?

[ubermonkey]

Not really my problem.

But any bulk mailer that doesn't solve that problem is by definition a spam engine, and should probably be blocked at the ISP level.