在安装Postfix之前，请从服务器中删除SendMail。
因为sendmail是redhat/centoS中的默认MTA。

[Hyman@theitroad ~]# yum remove sendmail

准备工作：

• 邮件服务器应在DNS服务器中包含有效的MX记录。导航到此链接如何设置DNS服务器。
• 防火墙和selinux应该被禁用。

[Hyman@theitroad ~]# service iptables stop
[Hyman@theitroad ~]# service ip6tables stop
[Hyman@theitroad ~]# chkconfig iptables off
[Hyman@theitroad ~]# chkconfig ip6tables off

[Hyman@theitroad ~]# vi /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

重新启动服务器。

场景

在本教程中我的测试环境

• hostname = server.theitroad.com.
• IP地址= 192.168.1.200/24

我的服务器配置了DNS服务器中的正确MX记录。

安装

Postfix默认安装。
如果未安装，请使用以下命令安装Postfix。

[Hyman@theitroad ~]# yum install postfix

配置

打开postfix config文件/etc/postfix/main.cf。
找到以下行并如下所示编辑它们。

[Hyman@theitroad ~]# vi /etc/postfix/main.cf
myhostname = server.theitroad.com ##line no 75 - uncomment and enter your host name
mydomain = theitroad.com  ##line no 83 - uncomment and enter your domain name 
myorigin = $mydomain  ##line no 99 - uncomment
inet_interfaces = all  ##line no 116 - change to all
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain  ##line no 164 - add $domain at the end
mynetworks = 192.168.1.0/24, 127.0.0.0/8  ##line no 264 - uncomment and add your network range
home_mailbox = Maildir/ ##line no 419 - uncomment

启动PostFix服务。

[Hyman@theitroad ~]# service postfix start
Starting postfix:                                          [  OK  ]
[Hyman@theitroad ~]# chkconfig postfix on

测试Postfix.

应由用户输入以粗体字母显示的命令。

注意：测试命令后的点很重要。

[Hyman@theitroad ~]# telnet localhost smtp
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 server.theitroad.com ESMTP Postfix
ehlo localhost
250-server.theitroad.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
mail from:<user1>
250 2.1.0 Ok
rcpt to:<user1>
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
test
.
250 2.0.0 Ok: queued as 117113FF18
quit
221 2.0.0 Bye
Connection closed by foreign host.

检查邮件

导航到用户邮件目录并检查新邮件。

[Hyman@theitroad ~]# cd /home/user1/Maildir/new/
[Hyman@theitroad new]# ls
1360236956.Vfd00I35afM181256.server.theitroad.com
[Hyman@theitroad new]# cat 1360236956.Vfd00I35afM181256.server.theitroad.com 
Return-Path: <Hyman@theitroad>
X-Original-To: user1
Delivered-To: Hyman@theitroad
Received: from localhost (localhost [IPv6:::1])
 by server.theitroad.com (Postfix) with ESMTP id 117113FF18
 for <user1>; Thu,  7 Nov 2013 17:05:32 +0530 (IST)
Message-Id: <Hyman@theitroad>
Date: Thu,  7 Nov 2013 17:05:32 +0530 (IST)
From: Hyman@theitroad
To: undisclosed-recipients:;
test

Postfix现在工作。

安装Dovecot.

[Hyman@theitroad ~]# yum install dovecot

配置Dovecot.

打开dovecot confif文件/etc/dovecot/dovecot.conf。
查找并取消注释如下所示。

[Hyman@theitroad ~]# vi /etc/dovecot/dovecot.conf
protocols = imap pop3 lmtp

打开file /etc/dovecot/conf.d/10-mail.conf并取消注释如下所示的行。

[Hyman@theitroad ~]# vi /etc/dovecot/conf.d/10-mail.conf
mail_location = maildir:~/Maildir  ##line no 24 - uncomment

打开/etc/dovecot/conf.d/10-auth.conf和编辑，如下所示。

[Hyman@theitroad ~]# vi /etc/dovecot/conf.d/10-auth.conf
disable_plaintext_auth = no  ##line no 9 - uncomment and change from yes to no.
auth_mechanisms = plain login  ##line no 97 - add the text "login"

如下所示，打开/etc/dovecot/conf.d/10-master.conf和编辑。

unix_listener auth-userdb {
    #mode = 0600
    user = postfix  ##line no 83 - uncomment and enter postfix
    group = postfix  ##line no 84 - uncomment and enter postfix

启动Dovecot服务。

[Hyman@theitroad ~]# service dovecot start
Starting Dovecot Imap:                                     [  OK  ]
[Hyman@theitroad ~]# chkconfig dovecot on

测试Dovecot.

应由用户输入粗体显示的命令。

[Hyman@theitroad ~]# telnet localhost pop3
Trying ::1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
user user1
+OK
pass user1
+OK Logged in.
list
+OK 1 messages:
1 428
.
retr 1
+OK 428 octets
Return-Path: <Hyman@theitroad>
X-Original-To: user1
Delivered-To: Hyman@theitroad
Received: from localhost (localhost [IPv6:::1])
 by server.theitroad.com (Postfix) with ESMTP id 117113FF18
 for <user1>; Thu,  7 Nov 2013 17:05:32 +0530 (IST)
Message-Id: <Hyman@theitroad>
Date: Thu,  7 Nov 2013 17:05:32 +0530 (IST)
From: Hyman@theitroad
To: undisclosed-recipients:;
test
.
quit 
+OK Logging out.
Connection closed by foreign host.
[Hyman@theitroad ~]#

Dovecot现在正在工作。

安装squirrelmail.

首先安装EPEL存储库。
并从epel存储库安装Squirrelmail包。

[Hyman@theitroad ~]# wget http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
[Hyman@theitroad ~]# rpm -ivh epel-release-6-8.noarch.rpm 
[Hyman@theitroad ~]# yum install squirrelmail
[Hyman@theitroad ~]# service httpd start
Starting httpd:                                            [  OK  ]
[Hyman@theitroad ~]# chkconfig httpd on
[Hyman@theitroad ~]#

配置squirrelmail.

转到SquirrelMail配置目录并使用命令./conf.pl开始配置，如下所示。

[Hyman@theitroad ~]# cd /usr/share/squirrelmail/config/
[Hyman@theitroad config]# ./conf.pl 
SquirrelMail Configuration : Read: config.php (1.4.0)
--------------------------------------------------------
Main Menu -
1.  Organization Preferences
2.  Server Settings
3.  Folder Defaults
4.  General Options
5.  Themes
6.  Address Books
7.  Message of the Day (MOTD)
8.  Plugins
9.  Database
10. Languages
D.  Set pre-defined settings for specific IMAP servers
C   Turn color off
S   Save data
Q   Quit
Command >>1

选择选项1并设置组织详细信息。

SquirrelMail Configuration : Read: config.php (1.4.0)
--------------------------------------------------------
Organization Preferences
1.  Organization Name      : theitroad
2.  Organization Logo      : ../images/sm_logo.png
3.  Org. Logo Width/Height : (308/111)
4.  Organization Title     : Welcome to theitroad webmail
5.  Signout Page           : 
6.  Top Frame              : _top
7.  Provider link          : https://theitroad.com
8.  Provider name          : theitroad
R   Return to Main Menu
C   Turn color off
S   Save data
Q   Quit
Command >>R

按R返回主菜单并选择选项2.输入域名，然后在SendMail或者SMTP参数中选择DoveCot。

SquirrelMail Configuration : Read: config.php (1.4.0)
--------------------------------------------------------
Server Settings
General
------
1.  Domain                 : theitroad.com
2.  Invert Time            : false
3.  Sendmail or SMTP       : SMTP
A.  Update IMAP Settings   : localhost:143 (uw)
B.  Update SMTP Settings   : localhost:25
R   Return to Main Menu
C   Turn color off
S   Save data
Q   Quit
Command >> S

完成后，按S保存数据，然后按Q退出。

最后在httpd.conf文件中添加以下行。

[Hyman@theitroad ~]# vi /etc/httpd/conf/httpd.conf
Alias /squirrelmail /usr/share/squirrelmail
<Directory /usr/share/squirrelmail>
    Options Indexes FollowSymLinks
    RewriteEngine On
    AllowOverride All
    DirectoryIndex index.php
    Order allow,deny
    Allow from all
</Directory>

重新启动httpd服务。

[Hyman@theitroad ~]# service httpd restart
Stopping httpd:                                            [  OK  ]
Starting httpd:                                            [  OK  ]
[Hyman@theitroad ~]#

创建用户

[Hyman@theitroad ~]# useradd user1
[Hyman@theitroad ~]# useradd user2
[Hyman@theitroad ~]# passwd user1
[Hyman@theitroad ~]# passwd user2

从任何客户端打开浏览器。
在地址列中键入以下内容。

http://serveripaddress/webmail

或者

http://yourdomainname/webmail

现在让我们从User1封装到User2.
请参阅下面的 Screen截图。

然后从User2注销并登录。

我们收到了User1的邮件。