GFI MailEssentials for Exchange/SMTP is a server based anti spam & email management solution for Microsoft Exchange Server & Notes/SMTP servers. Spam is caught before the mail server, no need to deploy client software. Its advanced Spam detection technology is based on: Content checking of body and subject for spam keywords, checking mail headers for typical spam practices, and checking if the sending mail server is on a third party black list such as ORDB. Admins can also set-up their own blacklists, as well as reduce false positives using the automatic whitelist feature.