"It's obvious by the amount of SMTP requests we blocked this year that
security at the connection level is the best way for corporations to stop spam
and virus threats," said Scott Petry, founder and senior vice president of
products and engineering at Postini.  "Content filtering by itself is
ineffective. As spammers get more sophisticated, customers like to know they
are protected at the connection level."
    In 2004 Postini also saw an increase in directory harvest attacks (DHAs),
an attempt by spammers to hijack and steal an enterprise's email directory to
send out spam.  Postini protected its customers from over 164 million DHAs and
blocked over 38 billion invalid delivery attempts.
    This past year saw the amount of legitimate email drop from 22% to just
12%, while viruses rose over the past year from roughly half a percent to one
and a half percent according to Postini's Email Stat Track. The virus
infection average ratio during 2004 was 1 in 67, compared to 2003, when 1 in
200 messages were infected with a virus. Towards the end of the year viruses
were infecting 1 in 25 emails.
    Currently, the company processes over 2.4 billion email messages per week,
and quarantines 88 percent of the messages as spam or viruses for leading
corporations and enterprises.

    Postini's Top Five 2005 Spam and Email Security Predictions

     1.  Legitimate email will drop from 12% to 8% of all email.
     2.  Directory harvest attacks will increase 25% while most victims won't
         realize they've been attacked.
     3. "Phishing" -- fraudulent email used to steal the recipient's identity
         information -- will rise significantly as well, recasting spam as a
         damaging activity rather than a nuisance.
     4.  Connection blocking technology will play an increasingly important
         role in protecting users from email threats of all types.
     5.  Corporations will continue to switch to managed perimeter defense
         services to protect employees from email-borne attacks.

    Postini's rapid growth from 2,000 customers in December 2003 to 4,100
customers in December 2004 underscores both the increasing importance
enterprises place on advanced email security and the effectiveness of
Postini's solution in stopping spam, viruses and other threats.  Awarded a
U.S. patent in March 2004 for its "preprocessing electronic messaging
solution," Perimeter Manager(TM) protects and secures email systems for over
6 million global users from malicious email attacks including spam, viruses,
phishing and directory harvest attacks.

    About Postini
    Postini, Inc. is the leading provider of email security and management
services that protect email infrastructure by preventing spam and attacks from
reaching the enterprise gateway.  Postini's patented managed services model
utilizes exclusive preEMPT(TM) transport and content filtering technology to
eliminate spam and viruses, stop DoS and directory harvest attacks, safeguard
content, and improve email performance.  Founded in 1999, Postini processes
more than 2.4 billion message connections every week for more than 4,000
companies. By blocking spam, viruses and attacks before they can reach the
enterprise email gateway, Postini Perimeter Manager is designed to assure
complete email security while saving bandwidth, conserving server capacity and
minimizing administrative costs.  For more information contact Postini at its
Redwood City, California headquarters toll-free at 866-767-8461, or visit
http://www.postini.com.

    Media Contacts:
     Marty Tacktill        Bryan Ferraro
     Postini, Inc.         Neale-May & Partners
     650-482-3197          650-328-5555 ext. 277
     marty@postini.com     bferraro@nealemay.com