I would like to know how to create an email notification when an incident has been in the "on hold" status for 3 days.
CA Service Desk Manager all versions
Currently there is no configurable way for configuring this kind of notification.
However, if you are sure that the ticket status life cycle is very simple and straight like open-->on hold-->closed, then you can use "Update Status" activity notification with some delay time.
You should not rely on end users to enter the status as that would break the status life cycle. You should use status transitions for that. For example, there are only two status transitions open-->on hold and on hold-->closed.