I'm unsure what problems Sendgrid is battling but their customer support staff is certainly understaffed or they simply gave up on fighting spam. So yes if you want to send spam and can start with highest paid account they offer, probably Sendgrid is your best bet.
Also their spam@ and abuse@ is a waste of time. It came to point that they simply started ignoring my inquiries at all! Here is example of one of my emails that is not getting any response, if Sendgrid is actually reading this: email@example.com
As sending spam is a Federal Crime, I have already reached out to FBI, FTC and next plan to write my State Attorney General.