如何处理垃圾？
垃圾邮件的分值处理比较麻烦，高了就把很多垃圾邮件给漏进来了，低了会阻挡一些中文邮件。
下面是/etc/amavis/conf.d/20-debian_defaults文件中的部分：
$sa_spam_subject_tag = '***SPAM*** ';
$sa_tag_level_deflt = 2.0; # add spam info headers if at, or above that level
$sa_tag2_level_deflt = 6.31; # add 'spam detected' headers at that level
$sa_kill_level_deflt = 6.31; # triggers spam evasive actions
$sa_dsn_cutoff_level = 10; # spam level beyond which a DSN is not sent
应该寻找一种办法，可以指定whitelist，现在指定whitelist好像不起作用。
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修改了/etc/spamassassin/nano local.cf文件，加入了：
whitelist_from *@lzb.ac.cn
还修改了/var/lib/amavis/.spamassassin/user_prefs文件，进行了同样的修改，不知道那个起作用。
这个文件内容如下：
# SpamAssassin config file for version 2.5x
# generated by http://www.yrex.com/spam/spamconfig.php (version 1.01)
# How many hits before a message is considered spam.
required_hits 5.0
# Whether to change the subject of suspected spam
rewrite_subject 1
# Text to prepend to subject if rewrite_subject is used
subject_tag *****SPAM*****
# Encapsulate spam in an attachment
report_safe 1
# Use terse version of the spam report
use_terse_report 0
# Enable the Bayes system
use_bayes 1
# Enable Bayes auto-learning
auto_learn 1
# Enable or disable network checks
skip_rbl_checks 0
use_razor2 1
use_dcc 1
use_pyzor 1
# Mail using languages used in these country codes will not be marked
# as being possibly spam in a foreign language.
# - chinese english
ok_languages zh en
# Mail using locales used in these country codes will not be marked
# as being possibly spam in a foreign language.
ok_locales en zh
body CH_FREE /免费/
describe CH_FREE Contain Chinese Free
score CH_FREE 3.0
score SUBJ_FULL_OF_8BITS 2
whitelist_from *@lzb.ac.cn