KB 437

Why can't you guys just filter out the spam!

 Article ID: 437
 Created: Aug-30-2006

Question or Symptoms

   It's easy to recognize, what's the big deal?

Resolution

   1. Humans pattern match really well.
   Here are two examples to think about in how you'd tell a computer to
   recognize them:
   -------------------------------------------------------------------------

   Aoccdrnig to a rscheearch at an Elingsh uinervtisy, it deosn't mttaer in
   waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht frist
   and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and
   you can sitll raed it wouthit porbelm. Tihs is bcuseae we do not raed ervey
   lteter by it slef but the wrod as a wlohe.

   ------------------------------------------------------------------------
   \/1agr@

   V`agra    V1agra    V iagra    v`aGra    `/1agra vi@gr@    v i a g r a
   vi agra    via gra    vi ag ra    V1 @g ra    V.I.A.G.R.A.
                __   __
   \\ //'  /\ | _+ |__| /\
    \/  | /--\|__| | \ /--\

    And these are just using plain ASCII text.
   ------------------------------------------------------------------------
   2. The spammers use the same tools we use to fight spam as test beds
      to craft spam. They have the same Bayesian filters, the same Spam
      Assassin pattern lists, the same virus signature databases and are
      updated in the same timely manner of new methods to catch spam.
      The difference is it's often their full time job to craft spam that
      can get through the current technology's filters, where as the folks
      fighting spam have fewer resources.

   ------------------------------------------------------------------------
   3. We have to deliver ALL your desired mail, NONE of the spam, AND
      we have to do it in a timely fashion. Here are some ways a message
      can be delayed.

        Did it get caught in the queue of one of our front end spam filtering
        appliances?

        Was it stuck behind hundreds of thousands of bounced messages sent
        offsite with a legal SWCP/NMIA/Thuntek email address as its reply-to?

        Was the mail server under a dictionary attack of an army of zombies
        controlled by a spammer trolling for valid email addresses?

        Were our anti-virus machines hobbled by a carefully crafted poison
        pattern embedded in a virus?

   This certainly doesn't mean we're surrendering in this war against spam!
   We're constantly trolling for new ways to filter without throwing out
   the good stuff. About every six months we beef up our email system by
   buying new machines and/or re-engineering our email systems.
    It's an unending war but we're committed to trying to deliver all your 
   desired email fast and spam free.