源码搭建全功能邮件系统（7）

十二 avamvis-new

1． 安装
# mkdir -p /var/amavis /var/amavis/tmp /var/amavis/var /var/amavis/db
# chown -R amavis:amavis /var/amavis
# chmod -R 750 /var/amavis

# cp amavisd /usr/local/sbin/
# chown root /usr/local/sbin/amavisd
# chmod 755 /usr/local/sbin/amavisd

# cp amavisd.conf /etc/
# chown root /etc/amavisd.conf
# chmod 644 /etc/amavisd.conf

# cp amavisd_init.sh /etc/init.d/amavisd
# chmod 744 /etc/init.d/amavisd
# chkconfig --add amavisd
# chkconfig --level 2345 amavisd on
# vim /etc/rc.d/init.d/amavisd
prog="/usr/local/sbin/amavisd"

病毒邮件存放目录
# mkdir /var/virusmails
# chown amavis:amavis /var/virusmails
# chmod 750 /var/virusmails

编辑/etc/amavisd.conf，修改下面这几行
# vim /etc/amavisd.conf
$daemon_user = 'amavis';
$daemon_group = 'amavis';
$mydomain = 'zhousonglinux.com';
$db_home = "$MYHOME/db";
$lock_file = "$MYHOME/var/amavisd.lock";
$pid_file = "$MYHOME/var/amavisd.pid";
$myhostname = 'mail.zhousonglinux.com';
@local_domains_maps = qw(.);
@mynetworks = qw( 127.0.0.0/8 );

对本地发出的邮件不进行内容过滤
$policy_bank{'MYNETS'} = { # mail originating from @mynetworks
originating => 1, # is true in MYNETS by default, but let's make it explicit
os_fingerprint_method => undef, # don't query p0f for internal clients
allow_disclaimers => 1, # enables disclaimer insertion if available
bypass_spam_checks_maps => [1],
bypass_banned_checks_maps => [1],
bypass_header_checks_maps => [1],
};

$sa_spam_modifies_subj = 0;
# 当邮件被认为是垃圾邮件时，是否修改邮件的主题
$remove_existing_x_scanned_headers= 1;
# 凡是经过 Amavisd 过滤的邮件，都会在邮件头中被加入一行邮件头信息
$remove_existing_spam_headers = 1;

# 修改投递/拦截的方法:
$final_virus_destiny = D_DISCARD;
$final_banned_destiny = D_DISCARD;
$final_spam_destiny = D_PASS;
$final_bad_header_destiny = D_PASS;

# 配置Amavisd与Clamav结合
['ClamAV-clamd',
\&ask_daemon, ["CONTSCAN {}\n", " /usr/local/clamav/var/run/clamd.socket "],
qr/\bOK$/, qr/\bFOUND$/,
qr/^.*?: (?!Infected Archive)(.*) FOUND$/ ],
);

@av_scanners_backup = (
['ClamAV-clamscan', 'clamscan',
"--stdout --no-summary -r --tempdir=$TEMPBASE {}",
[0], qr/:.*\sFOUND$/, qr/^.*?: (?!Infected Archive)(.*) FOUND$/ ],
);

amavisd.conf常用参数说明：

$max_servers = 10; 设置最大可使用的进程数
$sa_spam_subject_tag = '[SPAM] '; 加 [SPAM] 标记
$mydomain = 'mail.zhousonglinux.com'; 设置域名
$myhostname = 'mail.zhousonglinux.com'; 设置主机名
@local_domains_maps = qw(.); 对所有的域检查
$sa_tag2_level_deflt = 5.0; 超过这个分数，允许在邮件标题加入[SPAM] 标记
$sa_kill_level_deflt = 5.0; 超过这个分数，直接將信件备份后删除
$final_virus_destiny: 检测到病毒时的动作
$final_banned_destiny: 检测到受禁止的内容时的动作
$final_spam_destiny: 检测到垃圾邮件、广告邮件（spam）时的动作
$final_bad_header_destiny： 检测到不良信件时的动作

默认有以下几种动作：
D_PASS: 无论信件是否有问题，都会将信件发给收件人
D_DISCARD: 信件将被丢弃，并且不会告知收件人及发件人
D_BOUNCE: 信件不会发送给收件人，但会通知发件人邮件没有被投递
D_REJECT: 邮件不会被投递给收件人，但会通知发件人邮件被拒绝

注意事项：

上述$mydomain参数与$myhostname参数相同，主要是为了方便之后的病毒/垃圾汇报邮件发给系统管理员时，能投递到本地的别名里，再转交到虚拟域的特定用户。

配置[/b]Postfix [/b]集成[/b]amavisd-new[/b]
编辑master.cf文件：
# vim /etc/postfix/master.cf
增加如下内容：
smtp-amavis unix - - n - 3 smtp
-o smtp_data_done_timeout=1200
-o smtp_send_xforward_command=yes
-o disable_dns_lookups=yes
-o max_use=10

127.0.0.1:10025 inet n - n - - smtpd
-o content_filter=
-o local_recipient_maps=
-o relay_recipient_maps=
-o smtpd_restriction_classes=
-o smtpd_client_restrictions=
-o smtpd_helo_restrictions=
-o smtpd_sender_restrictions=
-o smtpd_recipient_restrictions=permit_mynetworks,reject
-o mynetworks=127.0.0.0/8
-o strict_rfc821_envelopes=yes
-o smtpd_error_sleep_time=0
-o smtpd_soft_error_limit=1001
-o smtpd_hard_error_limit=1000
-o receive_override_options=no_unknown_recipient_checks,no_header_body_checks

编辑main.cf文件：
# vim /etc/postfix/main.cf
增加如下内容：
# Content-Filter
content_filter = smtp-amavis:[127.0.0.1]:10024
receive_override_options = no_address_mappings
注意：receive_override_options 这里必须增加，禁止地址展开/影射，否则如果遇到别名的时候会引起冗余邮件的产生。
重启postfix ：
# postfix stop
#postfix start

测试amavis
# /usr/local/sbin/amavisd debug
/usr/local/sbin/amavisd debug 测试amavis。一般而言，测试皆不能正常进行，因为所需要的很多perl模块很可能没有被安装。还好，报错信息给出了所需的模块。然后缺少什么perl模块就装什么perl模块。
# telnet localhost 10024
Trying 127.0.0.1...
Connected to test.com (127.0.0.1).
Escape character is '^]'.
220 [127.0.0.1] ESMTP amavisd-new service ready
启动amavisd
#service amavisd start

测试[/b]Clamav[/b]
# telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 mail.extmail.org ESMTP Postfix - by extmail.org
mail from: michael_zhou@zhousonglinux.com << 输入内容
250 2.1.0 Ok
rcpt to: test@zhousonglinux.com << 输入内容
250 2.1.5 Ok
data << 输入内容
354 End data with .
X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H* << 输入内容
.
250 2.0.0 Ok: queued as BC24E85260
quit << 输入内容
221 2.0.0 Bye
Connection closed by foreign host.

在邮件日志里，应该有相应的信息出现：

Mar 22 06:43:15 localhost amavis[15405]: (15405-01) Blocked INFECTED (Eicar-Test-Signature), [192.168.0.235] ->, quarantine:
virus-mI6vbjkWZ2Tz, Message-ID: <003401c88c1a$74706360$eb00a8c0@nbk00045>, mail_id: mI6vbjkWZ2Tz, Hits: -, size: 1757, 474 ms

如果看到类似这样的日志，表明Clamav+Amavisd-new工作正常。