For starters, I think this component is a great start integrating with SendGrid.  I like the ability to send from multiple addresses rather than a single configuration as the default Outsystems way.  We have SendGrid configured there, but it is extremely limited.  I have a question and an idea.  First, the question:

Is there any way for you to easily be able to use the standard Outsystems email templates?  I'm not sure how to set those up for use through this API.  Obviously changes would need to be made, but I don't know how that would look.

Now, an idea:

One of the powerful features of SendGrid is suppression (unsubscribe) groups.  I think it would be amazing to incorporate that into this API.  In this case, a recipient could unsubscribe to a marketing email while still getting their invoices.  A challenge we currently have is that we have customers unsubscribe to something, then invoices won't send.  I would be will to assist in this improvement for future versions.