FastMail is much better than google mail because it's not fueling google's hegemony over the web. That you have to pay for it means their sustainability is not tied to abusing their users. If you want privacy in the way you seem to mean privacy (end-to-end no-trust async messaging) of course anything speaking SMTP isn't going to be "better for privacy", but those systems largely are incompatible with how 99% of the web wants to communicate with you.