How to change email template when emailing abandoned cart customers

[mrpluckytoy]

(Refer to images) 
When clicking on customers emails on the abandoned carts section I would like to have my own custom message that opens up on Outlook, instead of the "Complete your purchase while orders are still available"

How do I do this?

[whyshop]

It seems that  we can't  modify  this email  "body" text.It is hardcoded by Shopify.
Maybe you can try the official "Shopify Email" app to design "the abandoned carts" email template and send the email automatically