The best way to accomplish this would be to add a "Field Change Trigger" rule to the "After Save Item" event, and insert a "Notification" rule inside it. Here's what I did:
I added the “Field Change Trigger” rule to the “After Save Item” event, and inside that I added a “Notification” rule.
For the “Field Change Trigger” rule I added “Status” to the list of fields, and set the Condition field to be:
updatedFields.get("Status") != null && (updatedFields.get("Status")).equals("Reopened")
And the Notification rule would be constructed in the normal way by putting in your required information in the “Body” and “Subject” fields and selecting the users who will receive the message in the “Recipients” list.