Implemented Suggested 10/25/2019
When an email has failed to be delivered, the ticket should be reopened so we can follow up.
If it is not desired to reopen the ticket, then send failed email notification to Technician that sent the last reply and/or the Tech assigned to the ticket).
It would be very reasonable and useful if an reply email has failed to be delivered to the subscriber/subscribers then New reply “for technicians only” will be added to the ticket. With the message/notification that previous/last reply/email delivery has failed.
With this kind of method, the technicians for sure will know that the previous reply/message email was not delivered to the subscriber/subscribers.
The small exclamation mark symbol that is displayed (on the ticket page) in some failed delivery cases don’t do the job because first of all it will be shown only on the ticket page and not on the tickets list page. Technicians will see the exclamation mark symbol only on ticket page. But if the reply is sent by the technician then the technician has no reason to visit the ticket page before there is a new reply sent (received) from the ticket submitter.
So in the real life situation the technicians don’t have the information about the sent reply that has failed to be delivered.