Fellow artists, some of you have been sending emails that say: "blah blah #GDPR, I only use your email address to send emails about upcoming shows. If you want off this list, please reply with remove."

This is NOT compliant. The old regulations allowed people to opt-out. The new ones require everyone to affirmatively opt-in.

Your mailing lists will undoubtedly shrink, but at least you know everyone left is actively interested.