1. A method for controlling access to categorized messages, the method comprising: establishing, based on a number of electronic messages associated with a category, a message objective, wherein the message objective: comprises a set of rules to determine how an electronic message is shared; informs user association, message association, and message access rules for each of multiple categories; comprises an allow more objective to allow grouping of electronic messages without additional input from a message originator; comprises a share objective to allow the electronic message to be shared with users in addition to the message originator and a message recipient; and wherein an electronic message comprises a categories field and a message objectives field; receiving a change to the message objective; categorizing the electronic message into a number of categories according to the message objective, wherein each category comprises a number of electronic messages; grouping the electronic messages with other electronic messages in the multiple categories based on semantically similar message content; determining, based on the message objective, a number of users allowed access to the electronic message; removing a first user from the number of users allowed access to the electronic message based on the first user having not accessed the electronic message within a specified amount of time; adding a second user to the number of users allowed access to the electronic message by receiving a request from the second user registering interest in a category; and allowing the number of users to access the electronic message according to the message objective.