CUP O FLORA
We use this app to send regular emails to our customers and also offer discounts etc. So far it's been smooth. Still working on further automation and will update as we go.
Good support but product is limited to bringing across order Id, order date and customer email. Useful but not for ecommerce where you would ideally be able to target by product purchased etc (which can be done, but would involve manual imports or setting up an API etc).
SendInBlue is a great service overall and we will continue to use it for our newsletters etc. Just not for ecommerce.
I'm using the free version of this app, 5mb limit on photo uploads which has made it a little harder for me but still a very good app, easy to navigate.