How to run an agent from inside a mailbox

I have a scheduled agent placed in mail1.box. I know an agent cannot be automatically scheduled in mail1.box, so please tell me how to run this agent inside the mail1.box from UI.
Change the agent trigger from "On Schedule" to "On event," and then leave the default Runtime as "Action Menu selection." This will enable you to run your agent through the Notes UI.

This was first published in June 2005