1. A method comprising: a control center creating, without human interaction, bulk filters for groups of a plurality of received email messages, the control center comprising a computer system; the control center receiving a request from a mass mailer to perform a certified mass mailing, wherein the request includes a sample email message of the mass mailer, the mass mailer comprising a computer system; in response to receiving the request, the control center generating a key to be associated with the certified mass mailing and sending the key to the mass mailer; the control center distributing the created bulk filters, the sample email message, and the key to a plurality of mail servers; wherein the bulk filters are usable by a given one of the plurality of mail servers to determine whether messages received at the given mail server are bulk email messages; and wherein the given mail server is configured to identify a bulk email message as being part of the certified mass mailing by: comparing the bulk email message with one or more samples of certified mass mailings to determine whether a match is found between the bulk email message and the sample email message, wherein the one or more samples include the sample email message; in response to finding the match, determining whether the bulk email message includes the key associated with the certified mass mailing; and identifying the bulk email message as being part of the certified mass mailing in response to the bulk email message including the key associated with the certified mass mailing.