簡介

　　本文講述在安裝了Redhat Enterprice AS 4 U2的PC上，配置一臺Postfix郵件服務器的過程。實現(xiàn)虛擬域、虛擬用戶、POP3、POP3S、SMTP、SMTPS、IMAP、IMAPS、防毒、防SPAM、網(wǎng)頁郵件功能。

涉及的軟件
1. Redhat Enterprice AS 4 U2
2. Mysql
系統(tǒng)自帶
用于存儲虛擬域、虛擬用戶等信息。
3. Apache
系統(tǒng)自帶
運行網(wǎng)頁郵件SquirrelMail和PostfixAdmin時使用。
4. PHP
系統(tǒng)自帶
運行網(wǎng)頁郵件SquirrelMail和PostfixAdmin時使用。
5. Cyrus-sasl
系統(tǒng)自帶
實現(xiàn)帶驗證的SMTP時使用。
6. Courier authentication library
從http://www.courier-mta.org/ 下載
實現(xiàn)帶驗證的SMTP時使用。
7. Postfix
從http://postfix.org 下載
一個MTA，雖然RHEL 4 自帶Postfix，但因為其不支持SSL及Mysql，所以我們需要自行編譯。
8. PostfixAdmin
從http://postfixadmin.com/ 下載
虛擬域、虛擬用戶等信息是放在Mysql內(nèi)的，安裝PostfixAdmin后，就可以用瀏覽器管理這些信息。
9. SquirrelMail
系統(tǒng)自帶
一個基于IMAP的Webmail客戶端。
10. Dovecot
系統(tǒng)自帶
提供POP3，POP3S，IMAP，IMAPS功能。
11. F-prot
從http://www.f-prot.com 下載，Linux workstation 版?zhèn)€人使用是免費的
提供殺毒功能，據(jù)聞速度和病毒庫比開源的Clamav好。
12. SpamAssassin
系統(tǒng)自帶
提供過濾垃圾郵件功能。
13. MailScanner
從http://www.sng.ecs.soton.ac.uk/mailscanner/ 下載
Postfix 是使用MailScanner 調(diào)用f-prot 與SpamAssassin，或者其它調(diào)用方法效率更好，但MailScanner配置比較直觀，且近拿了一個大獎 http://www.linuxawards.co.uk/content/view/26/42/ 。

配置過程
1． 基本軟件安裝
安裝RHEL 4 U2，使用默認安裝，語系為簡體中文。關閉SE Linux，配置網(wǎng)卡，使其能訪問Internet。進入X window，開始->系統(tǒng)設置->添加/刪除應用程序，安裝上文中提及“系統(tǒng)自帶”的軟件，包括：
萬維網(wǎng)服務器：mysql & php 相關的
郵件服務器：SquirrelMail perl-cyrus
SQL 數(shù)據(jù)庫：全部。
下載其它需要的軟件。

2． 配置PostfixAdmin、Mysql、Apache
[root@localhost tmp]# tar xzf postfixadmin-2.1.0.tgz
[root@localhost tmp]# mv postfixadmin-2.1.0 /var/www/html/pa
[root@localhost tmp]# service mysqld start
[root@localhost tmp]# mysql -uroot http://localhost/pa，然后按提示增加兩個虛擬域名d1.com 和 d2.com，增加兩個虛擬用戶a@d1.com，b@d2.com。

設置Mysql和Apache自動啟動
[root@localhost tmp]# chkconfig --level 35 mysqld on
[root@localhost tmp]# chkconfig --level 35 httpd on

3． 編譯、配置Postfix
先刪除sendmail
[root@localhost tmp]# rpm –e sendmail –nodeps
[root@localhost tmp]# groupadd postfix
[root@localhost tmp]# groupadd postdrop
[root@localhost tmp]#useradd postfix -g postfix -c "Postfix user" -d /dev/null -s /sbin/nologin
[root@localhost tmp]# tar xzf postfix-2.2.7.tar.gz
[root@localhost tmp]# cd postfix-2.2.7
[root@localhost postfix-2.2.7]# make -f Makefile.init makefiles 'CCARGS=-DHAS_MYSQL -I/usr/include/mysql -DUSE_TLS -DUSE_SASL_AUTH -I/usr/include/sasl' 'AUXLIBS=-L/usr/lib/mysql -lmysqlclient -lz -lm -L/usr/lib -lssl -lcrypto -lsasl2'
[root@localhost postfix-2.2.7]# make
[root@localhost postfix-2.2.7]# make install
注：“make install”命令后的所有問題都直接敲回車鍵即可。

編輯/etc/postfix/main.cf 為以下內(nèi)容
#=====================BASE=========================
myhostname = mail.d1.com
mydomain = d1.com
myorigin = $mydomain
mydestination = $myhostname localhost localhost.$mydomain
mynetworks = 192.168.1.0/24 127.0.0.0/8
inet_interfaces = all
#=====================Vritual Mailbox settings=========================
virtual_mailbox_base = /var/spool/mail
virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf
virtual_alias_domains =
virtual_alias_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf
virtual_uid_maps = static:501
virtual_gid_maps = static:502
virtual_transport = virtual
maildrop_destination_recipient_limit = 1
maildrop_destination_concurrency_limit = 1
#====================QUOTA========================
message_size_limit = 14336000
virtual_mailbox_limit = 20971520
virtual_create_maildirsize = yes
virtual_mailbox_extended = yes
virtual_mailbox_limit_maps = mysql:/etc/postfix/mysql_virtual_mailbox_limit_maps.cf
virtual_mailbox_limit_override = yes
virtual_maildir_limit_message = Sorry, the user's maildir has overdrawn his diskspace quota, please try again later.
virtual_overquota_bounce = yes
#====================SASL========================
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_mynetworks,permit_sasl_authenticated,reject_invalid_hostname,reject_non_fqdn_hostname,reject_unknown_sender_domain,reject_non_fqdn_sender,reject_non_fqdn_recipient,reject_unknown_recipient_domain,reject_unauth_pipelining,reject_unauth_destination,permit
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = $myhostname
smtpd_sasl_security_options = noanonymous
smtpd_sasl_application_name = smtpd
smtpd_banner=$myhostname ESMTP "Version not Available"

readme_directory = no
sample_directory = /etc/postfix
sendmail_path = /usr/sbin/sendmail
html_directory = no
setgid_group = postdrop
command_directory = /usr/sbin
manpage_directory = /usr/local/man
daemon_directory = /usr/libexec/postfix
newaliases_path = /usr/bin/newaliases
mailq_path = /usr/bin/mailq
queue_directory = /var/spool/postfix
mail_owner = postfix

編輯/etc/postfix/ mysql_virtual_alias_maps.cf 為以下內(nèi)容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = alias
select_field = goto
where_field = address

編輯/etc/postfix/ mysql_virtual_domains_maps.cf 為以下內(nèi)容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = domain
select_field = description
where_field = domain

編輯/etc/postfix/ mysql_virtual_mailbox_limit_maps.cf 為以下內(nèi)容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = mailbox
select_field = quota
where_field = username

編輯/etc/postfix/ mysql_virtual_mailbox_maps.cf 為以下內(nèi)容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = mailbox
select_field = maildir
where_field = username

4． 配置SMTP 認證
編輯 /usr/lib/sasl2/smtpd.conf 為以下內(nèi)容
pwcheck_method: authdaemond
log_level: 3
mech_list: plain login
authdaemond_path:/usr/local/courier-authlib/var/spool/authdaemon/socket

安裝Courier authentication library
[root@localhost tmp]# tar jxf courier-authlib-0.58.tar.bz2
[root@localhost tmp]# cd courier-authlib-0.58
[root@localhost courier-authlib-0.58]# ./configure --prefix=/usr/local/courier-authlib --without-authpam --without-authldap --without-authpwd --without-authshadow --without-authvchkpw --without-authpgsql --with-authmysql --with-mysql-libs=/usr/lib/mysql --with-mysql-includes=/usr/include/mysql --with-redhat --with-authmysqlrc=/usr/local/courier-authlib/etc/authmysqlrc --with-authdaemonrc=/usr/local/courier-authlib/etc/authdaemonrc CFLAGS="-march=i686 -O2 -fexpensive-optimizations" CXXFLAGS="-march=i686 -O2 -fexpensive-optimizations"
[root@localhost courier-authlib-0.58]# make
[root@localhost courier-authlib-0.58]# make install
[root@localhost courier-authlib-0.58]# chmod 755 /usr/local/courier-authlib/var/spool/authdaemon
[root@localhost courier-authlib-0.58]# cp /usr/local/courier-authlib/etc/authdaemonrc.dist /usr/local/courier-authlib/etc/authdaemonrc

修改/usr/local/courier-authlib/etc/authdaemonrc 文件
authmodulelist="authmysql"
authmodulelistorig="authmysql"
daemons=10

編輯/usr/local/courier-authlib/etc/authmysqlrc 為以下內(nèi)容，其中501，502 為postfix 用戶的UID和GID。
MYSQL_SERVER localhost
MYSQL_USERNAME postfix
MYSQL_PASSWORD postfix
MYSQL_SOCKET /var/lib/mysql/mysql.sock
MYSQL_DATABASE postfix
MYSQL_USER_TABLE mailbox
MYSQL_CRYPT_PWFIELD password
MYSQL_UID_FIELD '501'
MYSQL_GID_FIELD '502'
MYSQL_LOGIN_FIELD username
MYSQL_HOME_FIELD concat('/var/spool/mail/',maildir)
MYSQL_MAILDIR_FIELD concat('/var/spool/mail/',maildir)
MYSQL_NAME_FIELD name

# cp courier-authlib.sysvinit /etc/init.d/courier-authlib
# chmod 755 /etc/init.d/courier-authlib
# chkconfig --add courier-authlib
# chkconfig --level 35 courier-authlib on
手動啟動服務：
# service courier-authlib start

此時你已經(jīng)擁有一臺帶驗證的SMTP 服務器，用Outlook 、Foxmail測試一下吧，用戶名采用usename@domainName.com 形式。

5． 增加SSL功能，配置SMTPS服務
在/etc/postfix/main.cf 增加以下內(nèi)容
smtp_use_tls = yes
smtpd_use_tls = yes
smtp_tls_note_starttls_offer = yes
smtpd_tls_key_file = /etc/ssl/smtpd.pem
smtpd_tls_cert_file = /etc/ssl/smtpd.pem
smtpd_tls_CAfile = /etc/ssl/smtpd.pem
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom

生成證書
# mkdir /etc/ssl
# cd /etc/ssl
# openssl req -new -x509 -nodes -out smtpd.pem -keyout smtpd.pem -days 3650

重新啟動postfix
# postfix reload

這時SMTPS功能應該能正常工作了。有能力測試的網(wǎng)友們請驗證一下這功能，因為使用SMTPS + Outlook 時有一錯誤提示。

6． 配置Dovecot，增加IMAP，IMAPS，POP3，POP3S功能
由于Dovecot 是系統(tǒng)自帶的，配置兩個文件，再生成證書就可以了。

編輯 /etc/dovecot.conf 為以下內(nèi)容
base_dir = /var/run/dovecot/
protocols = imap imaps pop3 pop3s
imap_listen = [::]
pop3_listen = [::]
ssl_disable = no
ssl_cert_file = /etc/ssl/certs/imapd.pem
ssl_key_file = /etc/ssl/private/imapd.pem
ssl_parameters_file = /var/run/dovecot/ssl-parameters.dat
login_dir = /var/run/dovecot-login
login = imap
login = pop3
mbox_locks = fcntl
auth = default
auth_mechanisms = plain
auth_userdb = passwd
auth_user = root
default_mail_env = maildir:/var/spool/mail/%u/
auth_userdb = mysql /etc/dovecot-mysql.conf
auth_passdb = mysql /etc/dovecot-mysql.conf
first_valid_uid = 501

編輯 /etc/dovecot-mysql.conf 為以下內(nèi)容
db_host = localhost
db_port = 3306
db_unix_socket = /var/lib/mysql/mysql.sock
db = postfix
db_user = postfix
db_passwd = postfix
db_client_flags = 0
default_pass_scheme = PLAIN-MD5
password_query = SELECT password FROM mailbox WHERE username = '%u'
user_query = SELECT maildir, 501 AS uid, 502 AS gid FROM mailbox WHERE username = '%u'

生成證書
# mkdir /etc/ssl/certs
# mkdir /etc/ssl private
# cd /usr/share/doc/dovecot-0.99.11/
# sh mkcert.sh

啟動Dovecot 服務
# service dovecot start
# chkconfig --level 35 dovecot on

順利的話，此時SMTP、SMTPS、POP3、POP3S已經(jīng)配置完成。

7． 配置SquirrelMail網(wǎng)頁郵件
很簡單，用瀏覽器訪問 http://localhost/webmail

8． 配置殺毒、過濾SPAM功能
如果你打算將殺毒、過濾SPAM功能安排在各個客戶端，以下是不必要操作的。

安裝f-prot
從http://files.f-prot.com/files/linux-x86/fp-linux-ws.rpm 下載
# rpm -ivh fp-linux-ws.rpm

啟動SpamAssassin
# service spamassassin start
# chkconfig --level 35 spamassassin on

安裝、配置MailScanner
# tar xzf MailScanner-4.48.4-2.rpm.tar.gz
# cd MailScanner-4.48.4-2
# ./install.sh

修改 /etc/MailScanner/MailScanner.conf
Run As User = postfix
Run As Group = postfix
Incoming Queue Dir = /var/spool/postfix/hold
Outgoing Queue Dir = /var/spool/postfix/incoming
MTA = postfix
Virus Scanners = f-prot
Always Include SpamAssassin Report = yes
Use SpamAssassin = yes
Required SpamAssassin Score = 4
SpamAssassin User State Dir = /var/spool/MailScanner/spamassassin
SpamAssassin Install Prefix = /usr/bin
SpamAssassin Local Rules Dir = /etc/MailScanner

讓Postfix 調(diào)用MailScanner，在/etc/postfix/main.cf 加入以下一行
header_checks = regexp:/etc/postfix/header_checks

編輯/etc/postfix/header_checks 為以下內(nèi)容
/^Received:/ HOLD

修正權限
# chown postfix.postfix /var/spool/MailScanner/incoming
# chown postfix.postfix /var/spool/MailScanner/quarantine

啟用
# postfix stop
# service MailScanner start
# chkconfig --level 35 MailScanner on

注：MailScanner 會自動啟動Postfix。

測試SpamAssassin
發(fā)一封郵件帶如下內(nèi)容，接收后，標題應該帶有標記：
XJS*C4JDBQADN1.NSBN3*2IDNEN*GTUBE-STANDARD-ANTI-UBE-TEST-EMAIL*C.34X

測試f-prot
升級病毒庫：
# /usr/local/f-prot/tools/check-updates.pl
訪問http://www.webmail.us/testvirus，申請寄一封帶virus 的郵件寄到自己的郵箱

9． 如果上面的操作順利，整個配置完成