Customer context: The customer is confronted with a technical issue where their emails are not being delivered, which leads to tickets reopening along with a system message "answer was not delivered".
Customer: Why are tickets being reopened with a system message saying "answer was not delivered"?
Answer: This issue is resultant of a feature that reopens the ticket when the email cannot be delivered to the recipient. The delivery report is delivered from the email server of the recipient address. This report can be found below the undelivered message; however, if there is too much text in the last reply, the report might be hidden. If that's the case, click on the "Show more" button (arrow icon) below the last reply to see the delivery report.