Postfix是Wietse Venema在IBM的GPL协议之下开发的MTA（邮件传输代理）软件。在其应该在RHEL 4的过程中存在着很繁琐的一个过程，所以针对在RHEL 4配置Postfix的问题，在下面的文章中进行了详细的分析过程：
1.RHEL 4配置Postfix基本软件安装
安装RHEL 4 U2，使用默认安装，语系为简体中文。关闭SE Linux，配置网卡，使其能访问Internet。进入X window，开始->系统设置->添加/删除应用程序，安装上文中提及“系统自带”的软件，包括： 万维网服务器：mysql & php 相关的 邮件服务器：SquirrelMail perl-cyrus SQL 数据库：全部。 下载其它需要的软件。
2．RHEL 4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 < /var/www/html/pa/DATABASE_MYSQL.TXT
◆[root@localhost tmp]# cp /var/www/html/pa/config.inc.php.sample /var/www/html/pa/config.inc.php
◆[root@localhost tmp]# service httpd start
打开浏览器访问 http://localhost/pa，然后按提示增加两个虚拟域名d1.com 和 d2.com，增加两个虚拟用户[email]a@d1.com[/email]，[email]b@d2.com[/email]。
设置Mysql和Apache自动启动
[root@localhost tmp]# chkconfig --level 35 mysqld on
[root@localhost tmp]# chkconfig --level 35 httpd on
3．RHEL 4配置Postfix编译、配置Postfix
先删除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”命令后的所有问题都直接敲回车键即可。
编辑/etc/postfix/main.cf 为以下内容
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
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
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
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
编辑/etc/postfix/ mysql_virtual_alias_maps.cf 为以下内容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = alias
select_field = goto
where_field = address
编辑/etc/postfix/ mysql_virtual_domains_maps.cf 为以下内容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = domain
select_field = description
where_field = domain
编辑/etc/postfix/ mysql_virtual_mailbox_limit_maps.cf 为以下内容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = mailbox
select_field = quota
where_field = username
编辑/etc/postfix/ mysql_virtual_mailbox_maps.cf 为以下内容
user = postfix
password = postfix
hosts = localhost
dbname = postfix
table = mailbox
select_field = maildir
where_field = username
4．RHEL 4配置Postfix要有SMTP 认证
编辑 /usr/lib/sasl2/smtpd.conf 为以下内容
pwcheck_method: authdaemond
log_level: 3
mech_list: plain login
authdaemond_path:/usr/local/courier-authlib/var/spool/authdaemon/socket
安装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
编辑/usr/local/courier-authlib/etc/authmysqlrc 为以下内容，其中501，502 为postfix 用户的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
手动启动服务：
# service courier-authlib start
此时你已经拥有一台带验证的SMTP 服务器，用Outlook 、Foxmail测试一下吧，用户名采用[email]usename@domainName.com[/email] 形式。
Postfix试图更快、更容易管理、更安全，同时还与sendmail保持足够的兼容性，所以RHEL 4配置Postfix是一个很重要的工作，在这里笔者对RHEL 4配置Postfix的过程用四个大部分进行了详细的描叙。
【编辑推荐】
