如何降低MSGID_FROM_MTA_ID和CHINA_HEADER评分

justkiding

在给mail.china.com发邮件时，我的邮件经常被判定为垃圾邮件，我发现其中MSGID_FROM_MTA_ID和CHINA_HEADER的评分比较高。

X-Spam-Score: 3.338
X-Spam-Level: ***
X-Spam-Status: No, score=3.338 tagged_above=2 required=5 tests=[AWL=0.967,
CHINA_HEADER=1.44, CN_BODY_129=0.001, CN_BODY_45=0.001,
HTML_MESSAGE=0.001, MIME_HTML_ONLY=0.001, MSGID_FROM_MTA_ID=0.927]

这个CHINA_HEADER估计是他们自己定义的一个策略，不清楚咋回事，但MSGID_FROM_MTA_ID的打分方法是怎么样的呢？
我grep了SA的代码，但只发现以下内容，只能看到定义，但看不到打分的方法

[root@localhost Mail-SpamAssassin-3.2.5]# grep "MSGID_FROM_MTA" * -r -i
rules/30_text_fr.cf:lang fr describe MSGID_FROM_MTA_HEADER      Message-ID ajout?par un relais
rules/STATISTICS-set2.txt:  1.011   1.3199   0.4666    0.739   0.48    1.50  MSGID_FROM_MTA_HEADER
rules/STATISTICS-set3.txt:  1.011   1.3199   0.4666    0.739   0.48    0.80  MSGID_FROM_MTA_HEADER
rules/50_scores.cf:score MSGID_FROM_MTA_HEADER 2.199 1.495 1.501 0.803
rules/30_text_pl.cf:lang pl describe MSGID_FROM_MTA_HEADER      Message-Id zosta?dodany przez relay
rules/STATISTICS-set0.txt:  1.011   1.3199   0.4666    0.739   0.48    2.20  MSGID_FROM_MTA_HEADER
rules/30_text_nl.cf:lang nl describe MSGID_FROM_MTA_HEADER           Message-Id was door een relay toegevoegd
rules/STATISTICS-set1.txt:  1.011   1.3199   0.4666    0.739   0.48    1.50  MSGID_FROM_MTA_HEADER
rules/20_head_tests.cf:meta MSGID_FROM_MTA_HEADER       (__MSGID_BEFORE_RECEIVED && !__MSGID_BEFORE_OKAY && !__FROM_HOTMAIL_COM)
rules/20_head_tests.cf:describe MSGID_FROM_MTA_HEADER   Message-Id was added by a relay
rules/30_text_de.cf:lang de describe MSGID_FROM_MTA_HEADER Kopfzeile "Message-ID" von fremdem Senderechner hinzugef黦t

还请高人指点一下如何降低这个分数，谢谢！