Bubble is pretty non-technical. The most technical it might get is reading some API documentation from other services. But, if I’m being for real and honest to you, I’d just ditch Sendgrid and go integrate Postmark- I just helped out @lihte with doing this.
Also check out this thread, might be more insight of whether you might want to stick with Sendgrid or go to Postmark. Postmark is awesome