How to Email Customer to Say Order Despatched?

On the Email management set up tab I’ve successfully set up a new pro-forma email to be sent to the customer to informa then their order has been despatched.

However I can’t see how to then make this happen?

Under the Email assignment it section, I expected to see an option under the “New Order” section that would then allow me to select the proforma I had created.

If I go to the order manager section I don’t see anything under “Actions” that allows me to then show the order is dispatched.

Am I missing something in how to set this up, or is this functionality not there?

I did see this this workaround in another post:

Sendmail

Is this a solution?

Many thanks

Neil