CentOS5.3+Nginx0.7.57+Postfix+Extmail邮件系统安装配置(四)-(注:里边一些内容引自原作者sery)

四.邮件反垃圾和反病毒

一． 邮件反病毒和垃圾邮件过滤
    1. 反病毒

抗病毒使用软件是 clamav

  下载： http://jaist.dl.sourceforge.net/sourceforge/clamav/clamav-0.95.tar.gz

　安装：
#################################################################
# tar zxvf clamav-0.95.tar.gz &&cd clamav-0.95*
# useradd clamav
# ./configure --prefix=/usr/local/clamav

--with-dbdir=/usr/local/share/clamav      // 定义病毒数据库目录

# make && make install
################################################################      
  基本配置：
 ###################################################################
  Clamav 有 2 个配置文件，一个主配置文件 /usr/local/clamav/etc/clamd.conf ，一个病毒更新配置文件  /usr/local/clamav/etc/ freshclam.conf 。现把修改好的配置文件列于下面：

[root@mail etc]# sed -e  '/^#/d' -e '/^$/d' clamd.conf

LogFile /var/log/clamav/clamd.log

LogSyslog yes

LogVerbose yes

PidFile /var/run/clamav/clamd.pid

DatabaseDirectory  /usr/local/share/clamav

LocalSocket /var/run/clamav/clamd.socket

StreamMaxLength 100M  // 附件大小 , 超过 100M 不扫描

User amavis

ScanMail yes

ScanArchive yes

[root@mail etc]# sed -e  '/^#/d' -e '/^$/d' freshclam.conf

DatabaseDirectory  /usr/local/share/clamav

UpdateLogFile  /var/log/clamav/freshclam.log

LogVerbose yes

LogSyslog yes

PidFile /var/run/clamav/freshclam.pid

DatabaseOwner amavis

DatabaseMirror db.CN.clamav.net

DatabaseMirror database.clamav.net
 ##################################################################
       这 2 个文件有很多注释，我用 sed 把它过滤掉了。 Clamd.conf 中，有 "User amavis" 这样一行。为什么不用默认的用户 clamav 而使用 amavis 呢？这样做的目的是为了与 amavis-new 结合在一起。既然没有这个用户，就手动创建一个（ useradd amavis ）。接下来需要手动创建一些目录并赋予相应的权限，用来记录日志等用途；我把它作成一个 shell 脚本，直接执行即可，脚本的内容如下所示：

######################################################

[root@mailserv2 ~]# more  /root/clamav.sh

#!/bin/bash

# create directory for clamav
mkdir /usr/local/share/clamav
mkdir /var/log/clamav

chmod -R 744 /var/log/clamav

chown -R amavis:amavis /var/log/clamav

chown -R amavis.amavis /usr/local/share/clamav

mkdir /var/run/clamav

chmod 700 /var/run/clamav

chown amavis.amavis /var/run/clamav

#####################################################

# /usr/local/clamav/bin/freshclam 手动更新病毒库。

2. 反垃圾
  下载： http://www.ijs.si/software/amavisd/amavisd-new-2.6.2.tar.gz

  安装：
#################################################################
通过脚本一步到位：注意目录及版本

[root@mail virus]# vi /usr/local/bin/amavis.sh

 

#!/bin/bash

 

cd /usr/local/src/virus

 

tar zxvf amavisd-new-2.6.2.tar.gz && cd amavisd*

 

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

 

mkdir /var/virusmails

chown amavis:amavis /var/virusmails

chmod 750 /var/virusmails
################################################################    
执行完脚本后别忘记检查一下是否都按我们的意愿工作，如 /usr/local/sbin 目录是否有文件 amavisd 。

 

Amavisd 的配置文件 /etc/amavisd.conf 比较复杂，需要修改的内容如下：

$max_servers=8; 
$daemon_user = 'amavis';
$daemon_group = 'amavis';
$mydomain = 'mail.test.com';
$db_home = "$MYHOME/db";
$inet_socket_port = 10024;
$sa_tag_level_deflt = 5.0; 
$sa_tag2_level_deflt = 6.2; 
$sa_kill_level_deflt = $sa_tag2_level_deflt;
$virus_admin = "virusalert@$mydomain";
$sa_spam_subject_tag = '***SPAM*** ';
$forward_method = 'smtp:127.0.0.1:10025'; 

$notify_method = $forward_method;
$final_virus_destiny = D_DISCARD;
$final_banned_destiny = D_DISCARD;
$final_spam_destiny = D_PASS;
['ClamAV-clamd',
&ask_daemon, ["CONTSCAN {}n", "/var/run/clamav/clamd"],
qr/bOK$/, qr/bFOUND$/,
qr/^.*?: (?!Infected Archive)(.*) FOUND$/ ],

上述修改确认无误后，执行 # /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。这时你需要到 www.cpan.org 下载相关的模块，然后安装 ; 也可能遇到包依赖，再下载依赖的包，安装这个依赖，再反回来安装先前那个包，如此反复，很是烦人，极考验人的耐性。等到 /usr/local/sbin/amavisd debug 输出没有错误方才完成。有另外一种方法，即运行 [root@mailserv2 ~]# perl -MCPAN -e shell ，然后执行 cpan> install Time::HiRes 这样的命令挨个安装缺少的 perl 模块。根据我的经验，这样干很耗时，并且有的模块用这种方法安装还不灵，所以还不如在网站下载模块安装有效。

# /usr/local/sbin/amavisd debug

ERROR: MISSING REQUIRED BASIC MODULES:

  IO::Stringy

  Compress::Zlib

  MIME::Words

  MIME::Head

  MIME::Body

  MIME::Entity

  MIME::Parser

  MIME::Decoder

  MIME::Decoder::Base64

  MIME::Decoder::Binary

  MIME::Decoder::QuotedPrint

  MIME::Decoder::NBit

  MIME::Decoder::UU

  MIME::Decoder::Gzip64

  Net::Server

  Net::Server::PreFork

BEGIN failed--compilation aborted at /usr/local/sbin/amavisd line 234.

根据以上缺少内容,边安装边调试

安装 Mail/SpamAssassin.pm 相关 perl 模块

REQUIRED module missing: HTML::Parser

optional module missing: Mail::SPF

optional module missing: Mail::SPF::Query

optional module missing: IP::Country

optional module missing: Razor2

optional module missing: Net::Ident

optional module missing: IO::Socket::INET6

optional module missing: IO::Socket::SSL

optional module missing: Mail::DomainKeys

optional module missing: Mail::DKIM

optional module missing: LWP::UserAgent

optional module missing: HTTP::Date

optional module missing: Archive::Tar

optional module missing: IO::Zlib

optional module missing: Encode::Detect

 

最终调试结果部分:

May 12 17:01:02.413 test.com /usr/local/sbin/amavisd[25969]: ANTI-VIRUS code      loaded

May 12 17:01:02.413 test.com /usr/local/sbin/amavisd[25969]: ANTI-SPAM code       loaded

May 12 17:01:02.414 test.com /usr/local/sbin/amavisd[25969]: ANTI-SPAM-SA code    loaded

 

              3. mail:: spamassassin 配置如下

                     # more /etc/mail/spamassassin/local.cf
                     #####################################

required_hits 5

use_bayes 1

bayes_auto_learn 1

skip_rbl_checks 0

use_razor2 1

use_pyzor 0

#####################################
# chown �CR amavis.amavis /usr/share/spamassassin
# chmod �CR 777  /usr/share/spamassassin
以上两步不这样做 ,mail:: spamassassin 配置文件不会起作用 .

         4. 添加postfix 反病毒和反垃圾
                        # more /etc/main.cf

content_filter = smtp-amavis:[127.0.0.1]:10024

max_use = 10

# more /etc/ postfix /master.cf

#                antispam                                                   #

 

#############################################################################

 

smtp-amavis unix - - n - 2 smtp

  -o smtp_data_done_timeout=1200

  -o smtp_send_xforward_command=yes

  -o disable_dns_lookups=yes

 

localhost:10025 inet n - n - - smtpd

  -o content_filter=

  -o local_recipient_maps=

  -o relay_recipient_maps=

  -o mynetworks=127.0.0.0/8

  -o smtpd_helo_restrictions=

  -o smtpd_client_restrictions=

  -o smtpd_sender_restrictions=

  -o smtpd_recipient_restrictions=permit_mynetworks,reject

  -o strict_rfc821_envelopes=yes

  -o smtpd_error_sleep_time=0

  -o smtpd_soft_error_limit=1001

  -o smtpd_hard_error_limit=1000

              5./etc/rc.local 起动文件

                     ###############################################

                     # Start Nginx+extmailcgi

/var/www/extsuite/extmail/dispatch-init start
/usr/local/nginx/sbin/nginx

 

 

# mysql

 /usr/local/mysql/bin/mysqld_safe --user=mysql &

 

# authlib

/usr/local/authlib/sbin/authdaemond start

 

# sasl

/usr/local/sbin/saslauthd -a shadow pam

 

# postfix

/usr/sbin/postfix start

 

# mailgraph

/usr/local/mailgraph_ext/mailgraph-init start

/usr/local/mailgraph_ext/qmonitor-init start

 

# spam

/usr/bin/spamd --daemonize --pidfile /var/run/spamd.pid

/usr/local/sbin/amavisd start

/usr/local/clamav/sbin/clamd

###############################################

测试一下反SPAM 效果, 以下是maillog 日志

May 12 17:22:05 MailSer1 postfix/smtpd[2354]: connect from m15-74.126.com[220.181.15.74]

May 12 17:22:05 MailSer1 postfix/smtpd[2354]: 66871816F: client=m15-74.126.com[220.181.15.74]

May 12 17:22:05 MailSer1 postfix/cleanup[2362]: 66871816F: message-id=<[email protected]>

May 12 17:22:05 MailSer1 postfix/qmgr[2184]: 66871816F: from=<[email protected]>, size=2233, nrcpt=1 (queue active)

May 12 17:22:05 MailSer1 postfix/smtpd[2354]: disconnect from m15-74.126.com[220.181.15.74]

May 12 17:22:10 MailSer1 postfix/smtpd[2367]: connect from MailSer1[127.0.0.1]

May 12 17:22:10 MailSer1 postfix/smtpd[2367]: 7C5D78174: client=MailSer1[127.0.0.1]

May 12 17:22:10 MailSer1 postfix/cleanup[2362]: 7C5D78174: message-id=<[email protected]>

May 12 17:22:10 MailSer1 postfix/qmgr[2184]: 7C5D78174: from=<[email protected]>, size=2669, nrcpt=1 (queue active)

May 12 17:22:10 MailSer1 amavis[2198]: (02198-01) Passed CLEAN, [220.181.15.74] [59.108.107.66] <[email protected]> -> [email protected], Message-ID: <[email protected]>, mail_id: cPEEodFuFjcK, Hits: 2.9, size: 2233, queued_as: 7C5D78174, 4948 ms

May 12 17:22:10 MailSer1 postfix/smtp[2364]: 66871816F: [email protected], relay=127.0.0.1[127.0.0.1]:10024, delay=5.2, delays=0.16/0.1/0.05/4.9, dsn=2.0.0, status=sent (250 2.0.0 Ok, id=02198-01, from MTA([127.0.0.1]:10025): 250 2.0.0 Ok: queued as 7C5D78174)

May 12 17:22:10 MailSer1 postfix/qmgr[2184]: 66871816F: removed

May 12 17:22:10 MailSer1 authdaemond: received userid lookup request: [email protected]

May 12 17:22:10 MailSer1 authdaemond: authmysql: trying this module

May 12 17:22:10 MailSer1 authdaemond: authmysqllib: connected. Versions: header 50041, client 50041, server 50041

May 12 17:22:10 MailSer1 authdaemond: SQL query: SELECT username, password, "", '1001', '1001', '/var/mailbox/', maildir, concat(quota,' S'), name, "" FROM mailbox WHERE username = '[email protected]'  AND (active='1')

May 12 17:22:10 MailSer1 authdaemond: Authenticated: sysusername=<null>, sysuserid=1001, sysgroupid=1001, homedir=/var/mailbox/, [email protected], fullname=test, maildir=mail.test.com/test/Maildir/, quota=5242880S S, options=<null>

May 12 17:22:10 MailSer1 authdaemond: Authenticated: clearpasswd=<null>, passwd=$1$92oqbXjU$g/EwkMIivyj0LPwVsP7CQ.

May 12 17:22:10 MailSer1 postfix/pipe[2370]: 7C5D78174: [email protected], relay=maildrop, delay=0.24, delays=0.04/0.09/0/0.11, dsn=2.0.0, status=sent (delivered via maildrop service)

May 12 17:22:10 MailSer1 postfix/qmgr[2184]: 7C5D78174: removed
可能出现的问题:

Hits 值总为 0, 可能是 mail:: spamassassin 没有起作用 , 查看一下 /usr/share/spamassassin/ 是否有访问权限 , 其属主为 amavis

6. 病毒库和反垃圾规则更新
              [root@MailSer1 ~]# crontab -l

0 0 1 * * root wget -N -P /usr/share/spamassassin www.ccert.edu.cn/spam/sa/Chinese_rules.cf;kill -HUP `cat /var/run/spamd.pid`

00 00 * * * /usr/local/clamav/bin/freshclam

 

补充：

垃圾邮件分捡：

# more /etc/maildroprc
logfile "/var/log/maildrop.log" 
if (/^X-Spam-Flag:.*YES/)
{
    exception {
        to "$HOME/$DEFAULT/.Junk/."
    }
}

 

到此，整个邮件系统安装基本完成，在安装过程中，参考了网上很多资料，同时也发现了许多问题!这几篇文章难免还有一些不足，我会不断完善，也欢迎大家指正！