A change in the workflow post function is the correct answer.

When a transition includes a post function that sends notifications or fires an event and that post function is removed or modified the notification will not be sent when the issue moves. Workflow post functions are the usual mechanism to trigger email notifications on status changes so altering them is the most likely reason Maya did not receive the expected message.

Incoming mail handlers were removed is not the most likely cause because incoming mail handlers control creating or updating issues from email rather than sending notifications when a workflow transition occurs.

The global email processor has been disabled would affect how incoming or queued mail is processed but it is not the typical cause for a missing transition notification. Outgoing notifications depend on the mail server and notification configuration and a post function change is a more direct explanation when a single transition stops sending emails.

The default notification email prefix was changed would only alter the subject prefix of notification emails and would not prevent the notification from being sent. A prefix change would not explain why Maya received no message at all.

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