1. A method for an email receiver to rate an email sender, the method comprising: receiving an email from an email server, a person sending said email being an email sender, and a person receiving said email being an email receiver; retrieving, in advance of said receiver opening said email, information associated with said receiver which indicates whether said sender is a person whose emails are to be rated by said receiver; and in response to said sender being a person whose emails are to be rated: retrieving a local overall rating from storage; determining whether a cumulative email rating score for said sender exists and, in response to said cumulative email rating score existing, retrieving said cumulative email rating score; displaying said cumulative email rating score on any of: said email and a pop-up window associated with said opened email; displaying a plurality of selectable rating categories, wherein said selectable rating categories comprise any of: usefulness, educational, motivational, helpfulness, productivity, and spelling/grammar; and in response to said receiver electing to rate said email from said sender: said receiver rating said email by selecting one of said displayed rating categories; and in response to said email having been rated: adding said rating to said cumulative email rating score; and updating a historical database with said cumulative email rating score.