Your reputation precedes you. This is the idea behind a new weapon in the war on spam and e-mail overload from IronPort Systems: reputation filtering. The IronPort C60 Messaging Gateway appliance controls the flow of e-mail coming into your network based on the reputations of the senders. Reputations are primarily established using data collected from more than 11,000 organizations that participate in IronPorts SenderBase network.
With this data, Senderbase can identify mail that appears to be coming from spammers. The more likely a message is spam, the longer the message is held in the delivery queue. Or it may not be delivered at all, depending on rules set by the C60s administrator.
The more untrustworthy a sender appears, the more stringent are the restrictions applied to that sender. The restrictions include throttling the maximum message acceptance rate, determining whether to scan content, limiting attachment size/type, and enforcing encryption.
Delaying mail delivery does not stop spam, which is why the C60 will include a licensed version of Brightmails antispam server beginning in September. Used in conjunction with Brightmail, IronPort hopes that reputation filtering and mail queuing will reduce false negatives—spam messages that dont get stopped.
Antispam tools often use rules to identify unsolicited mail, but spammers are always coming up with techniques to outwit the spam stoppers. By holding mail from questionable sources, IronPorts gateway gives the antispam engine time to update its rules. Mail from reputable sources will be passed through.
The C60 costs $55,000 and is targeted at large corporations. But IronPort plans to integrate reputation filtering with less costly appliances for smaller businesses in the near future.
