feed from a weather forecast system the sending message server 204 may have isolated the information that the weather is bad meaning that it may be raining a variable called e g u201c metro_web service u201d in a condition decision module may have been set to u201c rain u201d thus c2 may be verified and a decryption key to decrypt m2 may be sent by the sending message server 204 to the receiving message system 208 only m2 will be made readable or accessible by decrypting this message the other messages will not be readable or accessible and may optionally be deleted in another embodiment the user may delete them manually fig4 shows symbolically the sending of the key that related to the condition to the recipients message system 208 this key may be used to decrypt the message at the recipient message system 208 such that it may be readable by a user it should be noted that the condition may also require a reaction to external variable conditions instead of time conditions only for this purpose the sending message server 204 may receive external information 404 as discussed above this information may be based on virtually any receivable external information e g the condition may be related to a stock price received from e g an rss feed or from other external information sources in one embodiment one e mail may be.