Delivery Status Notification (Failure)

Address not found Your message wasn't delivered to notification@priority.facebookmail.com because the address couldn't be found, or is unable to receive mail. LEARN MORE This link will take you to a third-party site

The response from the remote server was: 550 5.1.1 RCP-P1 Recipient address does not exist https://www.facebook.com/postmaster/response_codes?ip=2a00:1450:4864:20::529#RCP-P1