Customer is running a process where an approval email is being sent out when a specific type of ticket has been created.
After the recipient is receiving the approval email they use a link in the email to respond to approve.
These emails are received by the MAPI Listener and processed via HEAT Messaging Center, which should update the ticket with the approval.
This has been working until a few days ago.
The tickets are now no longer updated with the approval.
Upon examining the HEAT Messaging Center's trace logs it shows that other emails are being received by the MAPI Listener, but the approval emails are not received, even though they are being sent to the same (correct) mailbox.
The customer had created a server rule for the mailbox to move these specific emails to a different folder after they were being received.
This caused the emails to be moved out of the Inbox before the MAPI Listener could process them.
Once this email rule was disabled, the approval emails were being read and processed again.