SonicWall announced Tuesday a new version of the e-mail security gateway software and appliance it acquired upon purchasing MailFrontier earlier this year.

SonicWall E-mail Security 5.0 includes new means for trapping spam and enhanced content-compliance features for outbound messages.

Among the new spam-detection features is an image-thumbprinting technology that helps catch image-based spam, or e-mail with text messages hidden inside an image that evade traditional spam filters. SonicWall collects feedback from its network of users regarding which of these e-mails with images are spam, and then blocks them accordingly, officials say.

In addition to reporting on image e-mails that are spam, users can report on those that aren’t, therefore reducing the potential for false positives, the company says.

The new feature is designed to help large and small organizations get a handle on  threats entering their organizations via e-mail. Company officials quote an IDC report that says IT managers now rank spam as the third-greatest threat to their organizations.

On the outbound e-mail end, Version 5.0 includes compliance features that help organizations enforce regulations such as the Sarbanes-Oxley Act, the Gramm-Leach-Bliley Act and the Health Insurance Portability and Accountability Act by flagging e-mails that may contain sensitive data protected by these laws. The product uses record ID matching to detect predefined values such as Social Security and credit card numbers, includes predefined dictionaries to match keywords, and includes predefined policies regarding content filtering, officials say.

Version 5.0 also adds the ability to encrypt outbound e-mails using Transport Layer Security or route an e-mail to a third-party encryption provider. An e-mail archiving option, compliance reporting and e-mail auditing have also been added, the company says.

The SonicWall E-mail Security suite is available as either a gateway appliance or gateway software, in versions for small and midsize business and for enterprises. Pricing for the software starts at $195 and for the appliance at $1,395; both require annual subscriptions to updates.

SonicWall competes with e-mail security vendors, including Proofpoint, IronPort, CipherTrust, Symantec and Barracuda. In addition to its e-mail security products, the company sells firewall/VPN appliances and content-filtering appliances.