A.An email that permanently bounced back to the sender because the address is invalid.

B.An email that is recognized, but returned to the sender because the mail server is temporarily unavailable

C.An email that is recognized, but returned to the sender because the recipient's mailbox is full.

D.An email that was sent to a prospect marked as opted out because they visited the unsubscribe page.

A.Send using a segmentation rule.

B.Send using the form's completion actions.

C.Send using an engagement program.

D.Use a dynamic list to use as a recipient list on an email send.

A.Create clear calls-to-action

B.Create mobile-friendly version of the email

C.Create a text version of the email

D.Remove the unsubscribe from the email

E.Add domain keys and SPF