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The syntax for enabling Subject rewriting has changed in 3.0.x, it is now a more generic rewrite_header option.
This is documented in the \[http://spamassassin.apache.org/full/3.0.x/dist/UPGRADE UPGRADE file\]: Wiki Markup
Wiki Markup The "rewrite_subject" and "subject_tag" configuration options were deprecated and are now removed. Instead, using "rewrite_header Subject \[your desired setting\]". e.g.
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rewrite_header Subject ****SPAM(SCORE)****unmigrated-wiki-markup
Warning: if you are running SA through amavisd or qmail-scanner, those apps do their own message rewriting and [SpamAssassin] cannot perform these rewrites. \[http://qmail-scanner.sourceforge.net/FAQ.php#cs Here\] is the FAQ entry for how to rewrite the subject in qmail-scanner.
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