I see a few solutions in the comments: but one thing that is not acknowledged is: "What do you do if the email service executes successfully but your server cra

I see a few solutions in the comments: but one thing that is not acknowledged is: "What do you do if the email service executes successfully but your server crashes before the POST is returned". I guess this isn't the worst thing in the world since that just means you send the email twice. Edit: Actually the worst case is pretty bad, you could accidentally double-charge a user using Stripe.