21. A computer-implemented method, comprising: analyzing electronic messages of a first user with respect to one or more features associated with the electronic messages; associating descriptive tags with the electronic messages of the first user based on the analyzing; and performing tasks with respect to the electronic messages of the first user, on behalf of the first user, based on the descriptive tags associated with the respective electronic messages; wherein the analyzing includes identifying a sender of a first electronic message received by the first user and determining relevance of the first electronic message with respect to the first user as a function of at least one of, a relationship between the sender and the first user within an implied social graph of electronic message users, a quality of the relationship between the sender and the first user, a syntactic structure of the first electronic message, metadata associated with the first electronic message, a language used in the first electronic message, a character set used in the first electronic message, an action taken by the first user with respect to a second electronic message for which one or more features are similar to one or more corresponding features of the first electronic message, and an action taken by a second user with respect to an electronic message received by the second user for which one or more features are similar to one or more corresponding features of the first electronic message.
27. The method of claim 21 , wherein the determining relevance includes: determining the relevance based at least in part on the quality of the relationship between the sender and the recipient.