[AMaViS-user] NULL spam_subject_tag still rewrites header (SQL)

[Joel <jdl...@ei...>]

I have set up Postfix/Amavis on openSuSE 11.2 with the SQL schema from
http://www.ijs.si/software/amavisd/README.sql-mysql.txt. I'd like to
include the X-Spam headers in all of my e-mail, at least initially while
I test things. I created a new policy with spam_tag_level=-999,
spam_tag2_level=3, and nothing in spam_subject_tag (so it takes the
default of NULL), and I get this on a mail sent with subject "test":

X-Spam-Flag: NO
X-Spam-Score: -1.975
X-Spam-Level: 
X-Spam-Status: No, score=-1.975 tagged_above=-999 required=3
	tests=[AM:BOOST=-4.155, AWL=-0.719, TVD_SPACE_RATIO=2.899]
	autolearn=no
X-Amavis-PenPals: age 6 14:47:14
...
Subject: ***SPAM*** test


This seems rather odd to me. It looks like I can make the subject
rewrite go away by changing spam_subject_tag to an empty string, but why
doesn't NULL do the same thing? And where is that '***SPAM*** ' prepend
coming from? I can't find that string anywhere in my amavisd.conf or
/etc/spamassassin/* (I've set $sa_spam_subject_tag to some other string,
but it does not appear to be used). If a NULL result from the SQL query
means "use the default found at X" I'm ok with that, but I'd like to
know where I should define that default.

Thanks,
Joel