SPAMfighter Mail Gateway is a “store-and-forward” SMTP server – which means it will accept incoming e-mails instead, scan the e-mail, and route the e-mail on to another SMTP server. During the installation – or on any point in time afterwards – configuration of where to route e-mails can be configured. Due to this “store-and-forward” (i.e. gateway) concept – an existing SMTP server must exist.