What is the definitive way to use Gmail with OAuth and Nodemailer?

Question

Desired Behaviour

Use Gmail, OAuth2 and Nodemailer to send an email from a server side node.js f

Answer 1

OAuth Consent Screen

You are definetely right about the gaps and outdated information, and you did a really great job on documenting the steps needed to use Gmail with OAuth and nodemailer! Nevertheless, I think it worths mentioning that in the Credentials page there is another step: the OAuth Consent Screen tab.

It contains a form like a Google Play app submission that requires validation from Google, if you choose your app to not being validated, you have a limitation of 100 calls of what they call Sensitive scopes before being asked for submission.

What about quota?

It's still not clear to me if this 100 calls quota will be consumed even if you don't select any additional permission to use sensitive scopes (the default ones are email, profile, openid). I hope not, since the OAuth Consent Screen asks for things like the Application Homepage Link and Authorised domains that is something you might not have if you are working on a backend application.

I think that this whole procedure is really slow and uselessly complex since most people do all these steps to just send an email from their app using nodemailer...