Google Message Security for Google Apps Administration Guide - Manual (Page 403)

Interpreting Header Fields 403
Spam Filters
• S = General/bulk spam score
• CV = Internal use only. This has no effect on the overall spam score or
message disposition.
• P = Sexually explicit (pornography) spam score
• M = Make-money-fast (MMF) spam score
• C = Commercial or “special offer” spam score
• R = Racially insensitive spam score
Spam Scores
A spam score of 100 on the S filter would indicate that this email contains nothing
that triggers the general spam filter (it is a valid message). The lower the score,
the more likely that this message is spam.
Category Scores
A message is assigned to a filter category when its score in that category is an 85
or below.
Example:
X-pstn-levels: (S: 0.00000/60.95723 CV:99.9000 R:95.91080
P:95.91081 M:64.93900 C:93.23770 )
X-pstn-settings: 5 (2.00000:8.00000) r p M c
The overall spam score is S: 0.00000. This is a Make-Money-Fast (M) spam
message, as shown by the capital M in the X-pstn-settings line.
A score of 85 or below triggers a category filter and in this example the Make-
Money-Fast score is
M:64.9390 .
The X-pstn-levels header field is not added if one of the recipients has Bulk Email
protection disabled. For example, if the email message is sent to two users, one
with the Bulk Email filter turned on and one with it turned off, the message service
does not include this header field.
Blatant Spam Blocking (BSB) Score
A second numeric evaluation, the BSB score, appears after the spam score in the
X-pstn-levels header field. The BSB score is used by the spam engine to identify
messages that should be bounced or blackholed by Blatant Spam Blocking.
Unlike the spam score, the BSB score should not be evaluated directly.
Example:
X-pstn-levels: (S: 0.00010/62.95723 )
The spam score ( S: ) is separated from the BSB score by a slash (“/”). The BSB
score will always appear, even if BSB is not turned on.