My domain's SPF says "email from sendgrid is allowed", which allows anyone with a sendgrid account to spoof me. I didn't set up DKIM because I don't particular

My domain's SPF says "email from sendgrid is allowed", which allows anyone with a sendgrid account to spoof me. I didn't set up DKIM because I don't particularly care about the security of that particular domain. But the point is that you can't know how secure the domain is just because it has some security feature present like SPF.