Embodiments of the present invention provide a method, system and computer program product for sideband control of a secured e-mail message. In an embodiment of the invention, a method for sideband control of a secured e-mail message is provided. The method includes receiving a secured form of a message from a sender in an e-mail client executing in memory by at least one processor of a computer. The method also includes rendering the secured form of the message comprehensible only subsequent to the establishment of a sideband channel of communication with the sender.