I had situations in the past where I was required to send a notification directly from an expression. After some trial and error, I managed to find a way. Here is an example of how to send a notification directly from an expression. The first thing I did was to create a library rule. The purpose is to have all the code in one place, in case I need to make any changes down the road. Otherwise, I will have to replicate the change in all the expressions where I’ve used the email method.