US Patent 7899868 Method and apparatus for defining messaging identities

A method and apparatus for creating a catalog for use with at least one computer system that manages a plurality of email messages. The catalog provides an index into the plurality of email messages, and comprises a plurality of identifiers that each identifies an entity. The catalog also correlates at least some of the plurality of identifiers to corresponding email addresses. The method for creating a catalog comprises creating the catalog to include information defining a temporal interval during which at least one email address corresponds to a first entity.