E-mail security vendor Cloudmark on Tuesday released an upgrade to its Authority software that includes an e-mail rescanning feature designed to catch the latest Internet threats.

Authority 2.0 can rescan inbound messages to check for spam, phishing, viruses and other threats just before a recipient opens a message, says Jamie de Guerre, Cloudmark’s vice president of technology services.

The software scans inbound messages a first time and creates a “fingerprint” of each message that gets stored in the header. Before the recipient opens the message, the header information can be scanned a second time to check against new data Cloudmark has gathered regarding e-mail threats since the message was first checked, de Guerre says.

“Today’s battle with spam is very much a response-time battle; if we can respond quickly we can stop attacks,” de Guerre says. Cloudmark constantly collects data about new Internet threats from its Network Feedback System, to which participants report spam, viruses and other malware.

E-mail administrators can decide to schedule the rescan to occur just before a message is downloaded or even after a message is in the user’s in-box, in which case Authority will notify the user that the message should be quarantined or deleted, de Guerre says.

The rescanning feature is mainly targeted at ISPs, whose subscribers tend to check their e-mail less frequently than corporate users. However, Cloudmark also has signed up a number of enterprise resellers who will offer Authority 2.0 to their customers as well.