There are several parts of this I disagree with, but the one I disagree with the most is onboarding emails. Can I use your product in the email? No? Then don't

There are several parts of this I disagree with, but the one I disagree with the most is onboarding emails. Can I use your product in the email? No? Then don't send me an onboarding email, do the onboarding in-product with overlays when I log into it for the first time. Google does this with some success for Gmail if I recall correctly, it has arrows pointing at different sections and everything, and you can click to dismiss them. Bombarding the consumer with multiple onboarding emails may generate a high click rate, but if your target market has people that hate spam, it will instantly leave a bad taste in their mouth. It really sucks when I sign up for a new product I am peripherally interested in, and they clutter up my empty inbox with 5 enthusiastic emails, none of which has any content that I can actually use -- just links to the website.