Hi @Will_Hunt You can do it with the help of shopify flow and the email will be sent from shopify email, in this way all the things will be managed in shopify you don’t need to add some 3rd party app in your store.
Regarding how to setup the flow trigger: It will be the same way as you have written in your question i.e.
Order Delivered / Wait 30 Days / Email internal team member
OR
Order Created / Wait 45 Days (to allow for production) /Email internal team member
If you will unable to implement the same then I’m happy to do this for you, let me know. I can implement the flow changes so that this will work well for you.
Hopefully it will help you. If yes then Please don’t forget hit Like and Mark it as solution!
There is not an Order delivered trigger yet, as there is not an event for that. You could use Order fulfilled instead, which is probably close enough.
If the emails are internal, you can use the “Send internal email” action. You probably want to add conditions to check if the order contains the sample item.