/me looks at his work gmail account that regularly spam filters emails from github, and emails from his work google apps domain that pass DMARC, DKIM and SPF.
Nobody can send emails to Gmail with any certainty. Not even Google.
Nobody can send emails to Gmail with any certainty. Not even Google.
I'm guessing spammers may use Google Docs comments as a platform, but have never seen actual unsolicited Docs comments.