En esta entrada, vamos recopilando los mensajes de error más habituales que recibimos cuando nos viene un mensaje devuelto (bounce)
El usuario tiene el buzón lleno:
Diagnostic-Code: smtp; 550 User quota exceeded
El buzón no existe:
said: 552 1 Requested mail action aborted, mailbox not found (in reply t
Recipient address rejected: user unknown (in reply to RCPT TO command)
Diagnostic-Code: smtp; 511 5.1.1 : Recipient address rejected: user unknown
Diagnostic-Code: smtp; 550-5.1.1 The email account that you tried to reach does
not exist. Please try 550-5.1.1 double-checking the recipient's email
address for typos or 550-5.1.1 unnecessary spaces. Learn more at 550 5.1.1