How do I know if I need to re-send an email to a recipient?

Any message that has not been delivered to a recipient will receive a message that looks similar to the image below with the phrase "The following addresses had permanent failures":

 

This message is very similar to a "Return to Sender" stamp on a letter from the Post Office. If you received a message deilvery failure message, you can resend the same message. Click here to learn how to re-send an email to a recipient.