Security vendor CipherTrust on Monday released a free toolbar for Microsoft Outlook and Lotus Notes that graphically displays the likelihood that individual messages are spam or phishing attacks.

Powered by the Atlanta-based company's TrustedSource e-mail reputation engine, the toolbar offers recommendations on the legitimacy of each message that hits an Outlook or Notes inbox, said CipherTrust. TrustedSource assigns a "reputation score" to each message, and classifies senders based on its own analysis.

Such e-mail reputation schemes have been hot topics in the past -- most notably in 2004 as Microsoft and Yahoo pitched their Sender ID and DomainKeys ideas, respectively -- but progress has cooled significantly since 2004.

The CipherTrust toolbar also includes buttons to report messages as spam or phishing e-mail.

"Even with 99 percent catch rates, one in every 100 unwanted messages will make it to the user's desktop, highlighting an increasing need to provide additional information about the reputation of the sender and the message before the user interacts," said Paul Judge, CipherTrust's chief technology officer, in a statement.

The toolbar can be downloaded from CipherTrust's site; users must register by providing name, e-mail address, and phone number to access the download. A version for Web-based e-mail services, such as Hotmail and Yahoo Mail, is in development and scheduled to release next quarter.