Go to Settings > Notifications then disable those:
All Chess.Com Email Notifications Are Off But I Still Get Emails?

Did you read my post? "I have unchecked literally every box under email in Settings / Notifications."
Sorry I misunderstood then. I guess contact chess.com for best answer:
https://support.chess.com/article/295-how-do-i-report-a-bug-or-make-a-suggestion
I can't get Chess.com to stop sending me emails. I have unchecked literally every box under email in Settings / Notifications. This morning I got a 'Take a 1-min Survey For a Chance to Win a Free Diamond Membership' email. Make it stop!