A list of terms you should know.
Like any other specialized field, spam-fighting has developed its own
terminology. Here’s a quick guide to some of the terms you may encounter
when researching anti-spam products.
Bayesian. Bayesian analysis looks at relative
word frequencies between good and bad e-mail to determine whether a particular
e-mail is most likely spam or not. See the sidebar, “Understanding Bayesian
Blacklist. A list of addresses from which
e-mail should never be accepted.
DNSBL. DNS Black List. An automated service
that returns a code specifying whether it thinks a particular IP address
belongs to a spammer. See the sidebar, “Using DNSBLs.”
False negative. Mail that should have been
recognized as spam, but which was delivered as regular e-mail instead.
False positive. Mail that should have been
delivered, but which was erroneously recognized as spam. Most users find
false positives to be far worse than false negatives.
Ham. E-mail that the user wants to receive
(the opposite of spam).
Quarantine. A holding pen for messages,
from which they can be deleted or approved for delivery, either by the
systems administrator or by an individual user.
Spam. Undesired e-mail of any sort. Sometimes
called UCE or Unsolicited Commercial E-mail.
Web beacon. A single pixel linked image
in an HTML e-mail. This is invisible to the user, but serves to tell the
sender when a piece of mail has been opened.
Whitelist. A list of addresses from which
e-mail should always be accepted.
For more terminology and a catalog of spammers’ tricks for disguising
their e-mails, see ActiveState’s “Field Guide to Spam” at www.activestate.com/Products/PureMessage/Field_Guide_to_Spam/?_x=1.
Mike Gunderloy, MCSE, MCSD, MCDBA, is a former MCP columnist and the author of numerous development books.