Yup, I've watched mail that I send be delivered directly to Gmail inboxes even if I spoof the From address to be from a Gmail account. (Admittedly, the rest of

Yup, I've watched mail that I send be delivered directly to Gmail inboxes even if I spoof the From address to be from a Gmail account. (Admittedly, the rest of the headers show it correctly coming from the uwaterloo.ca mailservers, which are perhaps whitelisted, and the content of the email is never obviously spammy.)