Some A-hole has generated a couple of certificates but used my email address to create them, so I am now receiving renewal notices for “7f.ddns.net” and “server.narduzzi.ca”. However I do have domains of my own I use Lets Encrypt for and DO want to receive those renewal notices. If I click the 'Stop receiving all email from this address" links at the bottom of the bogus notifications, will that kill everything coming to my address (including the legit ones I do want) or are the notifications tracked per cert-domain?
Do you have another email address you can use? E.g. can you change user@example.com to user+1234@example.com? You could update your account(s) and then unsubscribe the old email address.
How to update an account’s email address depends on the client, but Certbot for example should be able to do “certbot register --update-registration -m user+1234@example.com”. Or something like that.