Best practices for implementing messaging security

摘要

Most enterprises have some type of messaging security in the form of spam and virus filtering.When installing a new or replacement messag ing-ecurity system, key areas to pay attention to are performance, user experience, and management and operational costs. Performance is generally easy to manage.Aside from simply having enough hardware to do the job, there are three keys to keep performance up to par. rnFirst, some sort of reputation-based filtering should occur early in the transaction, certainly before the entire e-mail has been accepted by the messaging-security gateway.This single step will block 50% to 75% of incoming messages in a typical enterprise, giving a dramatic reduction in total load. Proper use of good reputation-based filtering products has an almost vanishingly low false-positive rate — far lower than the anti spam engines themselves. If reputation-based filtering is done properly it also only results in detectable false positives, because the sender gets notification from his own mail gateway that the message was blocked. This allows for quick remediation and is preferable to a typical anti spam/antivirus false positive, where the message goes into a black hole and is unlikely to be discovered. Antispam engines that can return their verdict before the message is fully accepted are even better, but for per formance reasons this is not yet a common strategy.