[root@localhost ~]# rpm -qa | grep postfix

[root@localhost ]# yum install -y postfix

Loaded plugins: fastestmirror, refresh-packagekit, security                                                 

Complete!

[root@localhost]#

[root@localhost ~]# gedit /etc/postfix/main.cf

mydomain = david.cn      //dns中的域名

myhostname = mailsrv.david.cn  //dns中的域名

mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain

inet_interfaces = all   //允許處理所有網路信息

inet_protocols = all    //允許ipv4和ipv6

mynetworks = 192.168.0.0/24, 127.0.0.0/8     //允許接入的ip段

[root@localhost ~]# gedit /etc/sysconfig/iptables

-A INPUT -m state --state NEW -m tcp -p tcp --dport 25 -j ACCEPT

[root@localhost ~]# service iptables restart

iptables：將鏈設置為政策 ACCEPT：filter nat                [確定]

iptables：清除防火墻規則：                                 [確定]

iptables：正在卸載模塊：                                   [確定]

iptables：應用防火墻規則：                                 [確定]

iptables：載入額外模塊：nf_conntrack_ftp                   [確定]

[root@localhost ~]# service postfix start

啟動postfix：                                             [確定]

[root@localhost ~]#

[root@localhost ~]# telnet 192.168.0.113 25    //ip是本機地址，25是端口號

Trying 192.168.0.113...

Connected to 192.168.0.113.

Escape character is '^]'.

220 mailsrv.david.cn ESMTP Postfix

[root@localhost ~]# mail david     //給david發信，確保此用戶存在Linux系統中。發信人是當前登錄的用戶root

Subject: test04       //標題

hello david           //內容

.                       //結束

EOT

[root@localhost ~]# mail -u david      //查看用戶david的信件

Heirloom Mail version 12.4 7/29/08.  Type ? for help.

"/var/mail/david": 5 messages 1 new

    1 root                  Thu Aug 16 17:07  21/692   "test"

    2 root                  Thu Aug 16 17:08  20/631   "test"

    3 root                  Thu Aug 16 17:10  20/602   "test"

    4 root                  Fri Aug 17 08:15  20/570   "test3"

>N  5 root                  Fri Aug 17 09:46  18/539   "test04"    //此信件是剛才收到的，由root用戶發出

&