A SECURE ELECTRONIC MAIL GATEWAY

摘要

A gateway (1) is connected in a local area network (3). It interacts with a local mail server (4) and remote servers via a firewall (5) and the Internet (6). It automatically generates certificates for senders on-the-fly. It also caches third party certificates so that they are available for sending encrypted and/or signed messages to remote recipients. The gateway (1) also automatically requests third party certificates on-the-fly when required for outgoing messages.