Pattern Matching | Pattern matching is a method of
describing a message in terms of its content. The spam filter
examines layout and organization, to identify the common
characteristics of spam. An advanced pattern matching engine simultaneously
applies thousands of algorithms during a single pass. The results
determine a probability rating, and assign the appropriate action.
Patterns are updated regularly to identify new tactics. |
Spam Definitions | Spam definitions are patterns used to
identify specific instances of spam. They detect multiple instances
of material considered sufficiently similar to be the same message;
for example, hoaxes and chain letters that may otherwise be
difficult to detect. Spam definitions are updated regularly. |
Real Time Black Lists | The Real Time Blackhole List (RBL),
DSBL and DNSBL are compilations of networks that either allow
spammers to use their systems to send spam, or have not taken
action to prevent spammers from abusing their systems. |
Heuristic Analysis | Heuristic analysis uses a series
of internal tests to determine the likelihood that a message is spam
. Each test is weighted with a point value to reduce false
positives. The total probability of spam is examined to determine
an overall score, and a mapping function assigns the appropriate
action. |