A concluding or terminating
This way you understand what type of issue you will be faced with and you can come to an appropriate stopping point in your work before responding.
You don't have to stop what you're doing to open the mail the second it arrives; the mail will still be there when you reach a natural stopping point.
Your first stopping point should be learning more about the Portuguese Water Dog breed.
Divide kids into teams, and designate a starting and stopping point.