ESCOM Granted Singapore Patent for Spam Filtering Technology

Business Wire, Sept 23, 2004

OAKTON, Va. -- ESCOM Corp. announced today that it has received its first international patent for its Active SMTP (ASMTP) spam filtering technology. The Singapore Registry of Patents issued patent number 89066, entitled "Electronic Message Filter Having a Whitelist Database and a Quarantine Mechanism." ESCOM received its first U.S. patent in November 2001 and has other U.S. and international patents pending.

The Singapore patent claims three filters that detect junk e-mail (spam) by testing the remote host and sender's address. These include: (1) a client filter that detects client computers pretending to be e-mail servers, (2) an address verification filter that detects nonexistent (hence forged) sender addresses, and (3) a relay filter that detects open relays.

By some estimates, as much as 80% of all spam is forwarded by compromised Microsoft systems (zombies). Most of these are clients that can be detected by the client filter. Most spam also has forged addresses that can be detected by the address verification filter.

"These filters work during the setup phase of the protocol, so ASMTP can block zombies and forged addresses without downloading the message itself," said ESCOM president Al Donaldson. "And since worms and viruses are often spread by e-mail from compromised clients, these same filters can stop new attacks before your antivirus solution can update its data files."

This technology is available today in ESCOM's ASMTP software. Patents and software are available for licensing.

About ESCOM Corporation

ESCOM Corporation is a privately held Internet technology company founded in 1988. ESCOM's customers include ISPs, state and federal government, education, and manufacturing and technology companies. See http:/www.escom.com/company.html for additional information.