How to change the email address that can receive certificate expiration notice.
And I have open the link on the buttom of email: "If you are receiving this email in error, unsubscribe at: http://delivery.letsencrypt.org/track/unsub.php?u=.....",than display "won't send email to this address".
Now,Can I recover receiving emails and change email addresses?
I don't have any personal knowledge of Synology, but hopefully there would be an option somewhere in it to tell it to send the account update request with a new email address. Maybe you'd have better luck on a Synology forum? Or maybe there's someone else here who knows more details.