Google Message Security for Google Apps Administration Guide - Manual (Page 408)

408 Message Security for Google Apps Administration Guide
The score for legal content category appears levels line, LC: 0.1839 . The score is
less than 85, which triggers the category. Because this category was triggered
and because the legal-content filter was set to the highest value, the effective
threshold on the settings line was set to zero (1.0000:0.0000). The effective
threshold is compared to the spam score. If the spam score is less than the
effective threshold, the message is spam. In this example, the spam score and
effective thresholds are both zero, so the message is considered valid and is
passed through to the recipient inbox.
Transport Header Field Example
In this header field example, Industry Heuristics for legal transport were turned on.
X-pstn-levels: (S: 0.0041/ 14.36962 R:95.9108 P:95.9108
M:99.4056 C:78.1961 )
X-pstn-settings: 3 (1.0000:2.0000) lt r p m C
The lt code on the settings line indicates that the legal transport category was
turned on, but not triggered (it would be LT if triggered). The transport categories
are not assigned numeric scores and don’t appear in the X-pstn-levels line.
General Transport Heuristics Header Fields
The General Transport Heuristics engine analyzes both the contents of a
message as well as the source of the message. Senders of ~100% valid email are
given a bias against being quarantined as spam. These “trusted senders” are not
added to a white list. These senders continue to be subject to spam filters, but the
general transport heuristic lowers the risk that email from valid senders might be
accidentally quarantined.
The purpose of general transport heuristics is to reduce false quarantines by
creating a “reputation” database of sender behavior.
If one of the general transport-heuristic categories triggers, it shows up like any
other category in the X-pstn-settings header field with a GT1, GT2, or GT3. GT
stands for General Transport, and the three categories indicate the level of trust,
with GT1 being the most trusted. Each of the levels has an assigned multiplier that
adjusts the spam threshold based on its level of trust. If a General Transport
heuristic has been triggered, the “GT” is capitalized.
Here's a sample header field where a General Heuristics category was triggered:
X-pstn-settings: 3 (1.0000:0.1000) s gt3 GT2 gt1 r p m C
All customers benefit from this feature. There are no configurations associated
with General Transport heuristics.
X-pstn-addresses Header Field
Following is an example of a X-pstn-addresses header field:
X-pstn-addresses: from [email protected] forward (user good)
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