Use the "Object Contacts", "Contacts", and/or "Contact Types" tabs of the "Default Delay Service Type Notification Rule for request/incident/problem" notification rule to specify the contacts to be notified whenever the service type of an incident is delayed.
For example, to notify the Requester of the incident, open the "Object Contacts" tab, click on the "Update Object Contacts" button, search for a contact using the displayed "Object Contact Notification Search" form, add an entry from the displayed list of Object Contacts to the list of Notification Recipients, and click OK.
After clicking "OK":
Note that the Access Type of contacts must allow the receipt of internal notifications whenever the "Internal" field of the activity notification is set to "Yes"; otherwise the contact would not receive the notification.
For example, to allow contacts which have an Access Type of "Employee" to receive a "Delay Service Type" activity notification for which "Internal" is set to "Yes", the access type must be set to "Receive Internal Notification" set to "Yes".