A time authority is established within a trusted time authority hierarchy which is periodically updated with the current date and time by the time authority. The user trusts the time authority and the associated hierarchy. Servers in the chain of the established authority are authorized to stamp a message with the time and date and encode the message so the recipient knows whether the message has been tampered with since the date stamp was attached. Existing browser security features are used to provide the tamper-proof mechanism. Messages are sent to trusted outgoing mail servers and are time stamped, encoded with the time authority's digital signature for tamper protection, and are also encrypted according to the user's preferences. The message is then routed to the intended recipient whose mail reader receives the message, decodes the time authority's digital signature for tamper detection, and decrypts the message if it has been encrypted. Incoming mail servers can also be added to the trusted time authority hierarchy. The incoming mail server time stamps incoming mail before forwarding it to the receiving user and sends a time stamped return receipt to the sender if the user has selected that option and the receiver permits it.