> The optimal email structure: - Greeting - Opening - Main body - Call to action

That is 100% opposite of "BLUF: A military standard to make writing more powerful" that was featured on HN yesterday. BLUF is a military communications acronym—it stands for “bottom line up front”—that’s designed to enforce speed and clarity in reports and emails.

https://news.ycombinator.com/item?id=20964907

GOMC is good working in the first cold email. I agree with you that BLUF is better, but if the recipient knows you.