HP Email Firewall Appliance Series Bedienungsanleitung PDF herunterladen (Seite 50)

50 CHAPTER 4: ANTI-SPAM CONFIGURATION

■ Redirect to: The message will be delivered to the mail address

specified in Action Data.

■ Reject mail: The mail will not be accepted and the connecting mail

server is forced to return it.

■ BCC (Blind Carbon Copy): The message will be copied to the mail

address specified in Action Data.

■ Action data — Depending on the specified action:

■ Modify Subject Header: The specified text will be inserted into the

subject line, such as [BULK].

■ Add header: A message header will be added with the specified

text, such as [BULK].

■ Redirect to: Send the message to a mailbox such as

STA STA (Statistical Token Analysis) is a sophisticated method of identifying

spam based on statistical analysis of mail content. Simple text matches

can lead to false positives because a word or phrase can have many

meanings depending on the context. STA provides a way to accurately

measure how likely any particular message is to be spam without having

to specify every word and phrase.

STA achieves this by deriving a measure of a word or phrase contributing

to the likelihood of a message being spam. This is based on the relative

frequency of words and phrases in a large number of spam messages.

From this analysis, it creates a table of “discriminators” (words associated

with spam) and associated measures of how likely a message is spam.

When a new incoming message is received, STA analyzes the message,

extracts the discriminators (words and phrases), finds their measures from

the table, and aggregates these measures to produce a spam metric for

the message between 1 and 100.

STA uses three sources of data to build its run-time database:

■ The initial database tables based on analysis of known spam.

■ Tables derived from an analysis of local legitimate mail. This is referred

to as “training.”

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HP Email Firewall Appliance Series Bedienungsanleitung Seite 50