Abstract: A system for denying or allowing delivery of an incoming electronic mail (e-mail) message that indicates a source e-mail server, source domain, and an addressee for the message. A central e-mail server registry database stores information for all e-mail servers authorized to send e-mail messages over the Internet. Each e-mail recipient can specify characteristics of domains that are authorized to send e-mail messages to the recipient. When an incoming e-mail message arrives at the recipient's e-mail server, the server accesses the registry database to determine whether the source e-mail server and/or domain are registered, and if so, whether the registration in good standing, and whether the source domain possesses the specified characteristics. If these conditions are not met, delivery of the e-mail is denied. Registered e-mail servers can download specified server information from the central registry and store it in a local registry.