System, method and program to limit rate of transferring messages from suspected spammers

Managing e-mails from a source suspected of sending spam. The e-mails are received at a firewall or router en route to a mail server. A determination is made whether a source has sent an e-mail which exhibits characteristics of spam. In response, subsequent e-mails from the source destined for the mail server are rate-limiting at the firewall or router such that the firewall or router limits a rate at which the subsequent e-mails are forwarded from the firewall or router to the mail server. The rate limit can be a limit on a number of e-mails per unit of time from the source that will be forwarded from the firewall or router to the mail server.