PS: The important thing here is that e.g. Gmail doesn't mark these emails as spam because both SPF and DKIM are legitimate.  Even the reverse DNS is correct (because of the Sendgrid relation).  The only thing about the email headers that gives this away is the Digital Ocean address.

(Of course the email is a blatant scam — I mean, if Coinbase could do a 50% profit in just 10 days they wouldn't need my money in the first place. Also, why do they ask me to send my investments to a Blockchain account? — but the email headers are well forged.)