Abstract: System for preventing and delaying distribution of computer viruses through electronic mails, includes a virus checking module and a curing inducement module for inducing a virus transmitting client. In system and method of this invention, an IP address of the virus transmitting client is stored as an infected IP address and a predetermined blocking time is imposed to the infected IP address. Until the blocking time has passed, normal messages having no virus from the infected IP address are not allowed to be processed.

Abstract: A connection request from a remote host is denied by an e-mail service system, if the number of connection request from the remote host exceeds a predetermined reference number, and the responsibility to re-send the denied e-mail is transferred to the requesting host. For the determination of connection permission or denial, the number of connection requests from the remote host is calculated with reference to corresponding to an IP address. By the IP filtering scheme, traffic of the e-mail service system can be effectively managed and controlled.