Patent ID: 7590697

Claim:
A mail server for preventing sending of e-mail from a source mail client to a destination mail client, the mail server comprising: client information storing means for storing a client identifier assigned to a specific destination mail client in association with an e-mail threshold service identifier, the e-mail threshold service identifier indicative of whether the specific destination mail client subscribes to an e-mail threshold-exceed service; receiving means for receiving an e-mail sent from a specific source mail client to the specific destination mail client; counting means for counting a number of e-mails sent by the specific source mail client during a set time period; threshold-exceeded flag storing means for, in a case that the number of e-mails counted for the specific source mail client exceeds a threshold, storing a threshold-exceeded flag in association with a client identifier assigned to the specific source mail client; period identifier outputting means for outputting a period identifier indicative of a specific time period; e-mail managing means for preventing to send the e-mail, wherein if the number of the e-mails counted for the specific source mail client exceeds the threshold for the specific time period, the threshold-exceeded flag storing means stores the period identifier output by the period identifier outputting means in association with the threshold-exceeded flag; and wherein the e-mail managing means prevents sending the email if the threshold-exceeded flag stored in association with the client identifier of the specific source mail client indicates that the threshold has been exceeded, if the e-mail threshold service identifier of the specific destination mail client indicates that the specific destination mail client subscribes to the e-mail threshold-exceed service, and if a period identifier output, indicative of a time period when the e-mail is received, by the period identifier outputting means matches the period identifier stored by the threshold-exceeded flag storing means in association with the threshold-exceeded flag.