F-SECURE ANTI-VIRUS FOR MICROSOFT EXCHANGE Administrator's Manual page 183

Drop message - The message is deleted.
Add X-Header with Specifies if the spam flag will be added to the
Spam flag mail as a X-Spam-Flag header in the following
format:
X-Spam-Flag: <flag>
where <flag> is either "YES" or "NO".
YES - the mail is considered spam.
NO - the mail is not considered spam.
Example: X-Spam-Flag: YES
Add X-Header with Specify if the summary of triggered hits will be
summary added to the mail as X-Spam-Status header in
the following format:
X-Spam-Status: <flag>, hits=<scr>
required=<sfl> tests=<tests>
where
Administering F-Secure Spam Control
<flag> is Yes or No,
<scr> is the spam confidence rating
returned by the spam scanner,
<sfl> is the current spam filtering level,
<tests> is the comma-separated list of
tests run against the mail.
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