Delivery Status Notification (Failure)

Address not found Your message wasn't delivered to acil777@gmail.com because the address couldn't be found, or is unable to receive mail. LEARN MORE

The response was: 550 5.1.1 The email account that you tried to reach does not exist. Please try double-checking the recipient's email address for typos or unnecessary spaces. Learn more at https://support.google.com/mail/?p=NoSuchUser b84-20020a251b57000000b00831829d2ca2sor3564361ybb.149 - gsmtp