95% of inbound email traffic to Gmail is encrypted with TLS. https://transparencyreport.google.com/safer-email/overview?hl=en https://transparencyreport.google

95% of inbound email traffic to Gmail is encrypted with TLS. https://transparencyreport.google.com/safer-email/overview?hl=en https://transparencyreport.google.com/safer-email/overview?h... Password reset emails are already extremely common and a way of implementing the "second factor only" method in the OP.