Patent attributes
An e-mail message is sent from a public e-mail address via the e-mail account of a user and delivered to an e-mail gateway. The message is destined for the e-mail account of a recipient. The gateway determines that the public e-mail address is on a list of users desiring two-factor authentication. The gateway determines that the message contains an anomaly indicating fraud or possible forgery. The gateway sends a two-factor authentication message to a hidden e-mail account of the user. The user reviews the message and responds with a confirmation message either confirming that the message is legitimate or indicating that it is a forgery. If the message is legitimate the gateway allows the message to be delivered to the recipient; if not, the message remains in quarantine and is not delivered. The gateway exists at the user's corporation, the recipient's corporation or is hosted at a third-party cloud service.
