Bounce Back Error Message When Trying to Send Emails Through Yahoo Mail
Can somebody please help me understand the bounce back error message found below.
I usually get this whenever I try to send emails to my friend.
What is so strange is that I have been sending emails to that email address for a long time now so I don't understand why it is now giving me an error message.
Sorry, we were unable to deliver your message to the following address [email protected]
Remote host said: 551 not our customer [RCPT_TO]"