How do I choose the emails a product sends?

Open Products & Pricing, edit the product and look at the Details tab. Three lists let you choose a service email for that product:

• Welcome Email: sent when a service of this product is set up.
• Termination Email: sent when the automatic job terminates an overdue service of this product. It is not sent when you or a client terminate a service by hand; send a message from the client's service tab for that. None sends nothing.
• Upgrade/Downgrade Email: sent when a service moves to this product from another one. The email can use the previous and the new product names. None sends nothing, which is how it starts.

Only service emails are listed: the built-in ones, the ones plugins add (Sell License adds three software license emails), and any template you made in the Service Email group under Email Templates.

Products you already had keep sending the built-in Service Terminated email when a service is terminated automatically.