Gentlemen, it turns out it is very hard to debug UNWANTED_LANGUAGE_BODY. They forgot to put debugging features in the code, apparently TextCat.pm.
Lately spamassassin has decided that several of my mails contain UNWANTED_LANGUAGE_BODY X-Spam-Languages: ja.shift-jis despite that being hogwash. Well I tried to debug using spamassassin -D And got as far as dbg: rules: ran eval rule UNWANTED_LANGUAGE_BODY ======> got hit (1) Further grepping led to TextCat.pm. Now we ask, exactly what caused TextCat.pm decide my message was Japanese? Do I have to post it here, full of its personal information, or is there some additional debugging flag I can set?