Message marked as spam with negative score

[Jose Angel Blanco González]

I am using MailScanner+ClamAv+SpamAssassin. All works fine except I am
receiveng messages marked as spam with negative scoring.
This is part of messge's header:

X-Treelogic-MailScanner-Information: Please contact the ISP for more
information
X-Treelogic-MailScanner: Found to be clean
X-Treelogic-MailScanner-SpamCheck: spam, SBL+XBL, SpamAssassin
(puntaje=-4.7,
 requerido 6, BAYES_00 -4.90, HTML_70_80 0.10, HTML_MESSAGE 0.10)

but the message is marked as spam

any idea??

Thanks

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