I think you can also report it to Google. Enough reports, and their email will automatically be flagged as spam. You can write them a nice email explaining how their absence of an unsubscribe button will ultimately hurt them when Gmail cuts them off from its users.
Report it to the FTC. The CAN-SPAM Act calls for something like a $50K fine for every email sent that doesn’t include a one-click unsubscribe button.
https://reportfraud.ftc.gov/
I think you can also report it to Google. Enough reports, and their email will automatically be flagged as spam. You can write them a nice email explaining how their absence of an unsubscribe button will ultimately hurt them when Gmail cuts them off from its users.
And quickly, before it’s closed down.
Is there a European equivalent?
It looks like the GDPR covers no unsubscribe option in emails
https://gdpr.eu/email-encryption/