How do I automatically send an email to customer who purchases a particular item?

[erinmarkland13]

Hello, I am new and setting up my Shopify store. 🙂 I sell digital products and would like to have a specific email sent to the customer when they order a specific product. 

For example, if someone purchases the item "Digital Download A" then I would like their order to trigger an auto email that sends instructions on how to access this specific item. 

Thank you so much for any insight! 

Erin