I appreciate the motivation behind this and the effort involved, but this is exactly what causes the stigma for the JS ecosystem.
“Fire off emails!”
It only works with Gmail, which will limit you. And only with user and pass, which is insecure.
No unsubscribe.
No persistence.
No SPF or DKIM, etc.
This is someone trying to solve a problem that has no real grasp of how big the scale of the problem is. There is a reason companies like Sendgrid exist, but we’re trying to recreate them for “hackers” and startups now. Great...