SonicWALL announced SonicWALL Email Security 6.2, which features the Bounce-Address-Tag-Validation (BATV) specification to combat an increase in Non-Delivery Report (NDR) spam or backscatter messages. With the BATV mechanism turned on, the product can distinguish a legitimate NDR message from an NDR spam message — dropping the connection from the NDR spam server.
NDR spam is yet another form of spam mimicking a useful email capability — the bounce back message received when a valid email is unable to make it to its final destination inbox. By implementing BATV, each outbound message is “tagged” with a private key, transparently to the sender.
Arriving NDR messages are checked for the “tag” to ensure the validity of the inbound NDR email with legitimate NDR messages being delivered to the receiver as desired. Because SonicWALL Email Security can process both inbound and outbound email on the same system the actual implementation of BATV can be seamless to the customer as well as the end-users of the system.
Andrew Klein, Email Security Product Manager for SonicWALL commented:
More than 90 percent of the email messages our customers receive are spam, phishing, viruses, or policy violations — simply junk mail. For NDR spam, the real solution is to not only to block invalid messages and allow legitimate ones, but to make the process easy for the administrator. With email security 6.2, administrators will no longer have to write, manage and update countless policies and rules for NDR spam. BATV is an easy and effective method to detect and drop fake NDR messages with minimal overhead and no additional administration.