邮件服务器的配置
邮件服务器
邮件服务器是一种用来负责电子邮件收发管理的设备。它比网络上的免费邮箱更安全和高效，因此一直是企业公司的必备设备。
https://baike.baidu.com/item/邮件服务器
邮件服务器工作原理
[email protected]用户写好一封Email发送到sohu的Smtp服务器
sohu的Smtp服务器开始处理[email protected] 用户的请求，它会根据收件人的地址判断，当前收件人是不是自己管辖的用户，如果是，就直接将Email存放到为该收件人的分配的邮箱空间当中。sohu的Smtp服务器判断收件人地址发现，这一封Email的收件人[email protected]是Sina的邮件服务器管理的，于是又将Email转发给Sina的Smtp服务器
Sina的Smtp服务器开始处理sohu的Smtp服务器发送过来的Email，Sina的Smtp服务器根据收件人的地址判断，发现收件人自己管辖的用户，于是就直接将Email存放到为[email protected] 用户的分配的邮箱空间当中
[email protected]用户将邮件发出去之后，就通知[email protected] 用户去收取。[email protected] 用户于是就连接上Sina的POP3服务器收取邮件
POP3服务器从[email protected] 用户的邮箱空间当中取出Email
POP3服务器将取出来的Email发给[email protected] 用户
邮件服务器相关组件及相关协议
组件：
MUA（Mail User Agent）：“邮件用户代理”MUA是用在客户端的软件 ，主要的功能就是接收邮件主机的电
子邮件，并提供用户浏览与编写邮件的功能
MDA（Mail Delivery Agent）：“邮件投递代理”将MTA接收的信件依照信件的流向（送到哪里）将该信件放
置到本机账户下的邮件文件中（收件箱），或者再经由MTA将信件送到下个MTA
MTA（Mail Transfer Agent）： MTA是用在邮件主机上的软件，主要的邮件服务器。MTA就是“邮件传送代
理”，负责用户寄信与收信
MRA(Mail Retrieval Agent)： 负责实现IMAP与POP3协议，与MUA进行交互 （Dovecot）
协议：
SMTP（Simple Mail Transfer Protocol）： 传输发送邮件所使用的标准协议
IMAP（Internet Message Access Protocol）： 接收邮件使用的标准协议之一
POP3（Post Office Protocol 3）： 接收邮件使用的标准协议之一
邮件服务器端口
SMTP TCP:25 SSL:994
IAMP TCP:143 SSL:993
POP TCP:110 SSL:995
邮件服务器软件
Sendmail 早期的Linux系统中，默认使用的发件服务是由Sendmail服务程序提供
Postfix 相较于Sendmail服务程序，Postfix服务程序减少了很多不必要的配置步骤，而且在稳定性、并发性
方面也有很大改进
TruboMail
Coremail
Exchange #微软
Extmail #开源
WebMail #开源
邮件客户端软件
Outlook
Foxmail
Mailbox
Thunderbird
邮件服务器的部署
1.关闭防火墙&Selinux
[root@linux ~]# systemctl stop firewalld
[root@linux ~]# setenforce 0
setenforce: SELinux is disabled
[root@linux ~]# getenforce
Disabled
2.安装Postfix、dovecot、cyrus-sasl
[root@linux ~]# yum install postfix dovecot cyrus-sasl-* -y
Loaded plugins: fastestmirror
c7 | 3.6 kB 00:00:00
Loading mirror speeds from cached hostfile
Package 2:postfix-2.10.1-6.el7.x86_64 already installed and latest version
Package cyrus-sasl-lib-2.1.26-21.el7.x86_64 already installed and latest version
Resolving Dependencies
--> Running transaction check
---> Package cyrus-sasl.x86_64 0:2.1.26-21.el7 will be installed
---> Package cyrus-sasl-devel.x86_64 0:2.1.26-21.el7 will be installed
---> Package cyrus-sasl-gssapi.x86_64 0:2.1.26-21.el7 will be installed
---> Package cyrus-sasl-md5.x86_64 0:2.1.26-21.el7 will be installed
---> Package cyrus-sasl-plain.x86_64 0:2.1.26-21.el7 will be installed
---> Package cyrus-sasl-scram.x86_64 0:2.1.26-21.el7 will be installed
---> Package dovecot.x86_64 1:2.2.10-8.el7 will be installed
--> Processing Dependency: libclucene-shared.so.1()(64bit) for package: 1:dovecot-2.2.10-8.el7.x86_64
--> Processing Dependency: libclucene-core.so.1()(64bit) for package: 1:dovecot-2.2.10-8.el7.x86_64
--> Running transaction check
---> Package clucene-core.x86_64 0:2.3.3.4-11.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==================================================================================
Package Arch Version Repository Size
==================================================================================
Installing:
cyrus-sasl x86_64 2.1.26-21.el7 c7 88 k
cyrus-sasl-devel x86_64 2.1.26-21.el7 c7 310 k
cyrus-sasl-gssapi x86_64 2.1.26-21.el7 c7 41 k
cyrus-sasl-md5 x86_64 2.1.26-21.el7 c7 56 k
cyrus-sasl-plain x86_64 2.1.26-21.el7 c7 38 k
cyrus-sasl-scram x86_64 2.1.26-21.el7 c7 42 k
dovecot x86_64 1:2.2.10-8.el7 c7 3.2 M
Installing for dependencies:
clucene-core x86_64 2.3.3.4-11.el7 c7 528 k
Transaction Summary
==================================================================================
Install 7 Packages (+1 Dependent package)
Total download size: 4.3 M
Installed size: 13 M
Downloading packages:
----------------------------------------------------------------------------------
Total 24 MB/s | 4.3 MB 00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : cyrus-sasl-2.1.26-21.el7.x86_64 1/8
Installing : clucene-core-2.3.3.4-11.el7.x86_64 2/8
Installing : 1:dovecot-2.2.10-8.el7.x86_64 3/8
Installing : cyrus-sasl-devel-2.1.26-21.el7.x86_64 4/8
Installing : cyrus-sasl-plain-2.1.26-21.el7.x86_64 5/8
Installing : cyrus-sasl-md5-2.1.26-21.el7.x86_64 6/8
Installing : cyrus-sasl-gssapi-2.1.26-21.el7.x86_64 7/8
Installing : cyrus-sasl-scram-2.1.26-21.el7.x86_64 8/8
Verifying : cyrus-sasl-scram-2.1.26-21.el7.x86_64 1/8
Verifying : cyrus-sasl-gssapi-2.1.26-21.el7.x86_64 2/8
Verifying : cyrus-sasl-md5-2.1.26-21.el7.x86_64 3/8
Verifying : clucene-core-2.3.3.4-11.el7.x86_64 4/8
Verifying : cyrus-sasl-plain-2.1.26-21.el7.x86_64 5/8
Verifying : cyrus-sasl-devel-2.1.26-21.el7.x86_64 6/8
Verifying : 1:dovecot-2.2.10-8.el7.x86_64 7/8
Verifying : cyrus-sasl-2.1.26-21.el7.x86_64 8/8
Installed:
cyrus-sasl.x86_64 0:2.1.26-21.el7
cyrus-sasl-devel.x86_64 0:2.1.26-21.el7
cyrus-sasl-gssapi.x86_64 0:2.1.26-21.el7
cyrus-sasl-md5.x86_64 0:2.1.26-21.el7
cyrus-sasl-plain.x86_64 0:2.1.26-21.el7
cyrus-sasl-scram.x86_64 0:2.1.26-21.el7
dovecot.x86_64 1:2.2.10-8.el7
Dependency Installed:
clucene-core.x86_64 0:2.3.3.4-11.el7
Complete!
3.配置DNS服务器
DNS服务器只用做正向解析
[root@linux ~]# vi /etc/named.conf
listen-on port 53 { any; };
allow-query { any; }; #只做这两项的更改
[root@linux ~]# vi /etc/named.rfc1912.zones
38 zone "bk.com" IN {
39 type master;
40 file "bk.com.zone";
41 allow-update { none; };
42 }; #在文件最后添加这几行内容
[root@linux ~]# cd /var/named/
[root@linux named]# cp -a named.localhost bk.com.zone
[root@linux named]# vi bk.com.zone
1 $TTL 1D
2 @ IN SOA bk.com. root.bk.com. (
3 0 ; serial
4 1D ; refresh
5 1H ; retry
6 1W ; expire
7 3H ) ; minimum
8 @ NS ns.bk.com.
9 ns IN A 192.168.130.128
10 IN MX 10 mail.bk.com.
11 mail IN A 192.168.130.128
[root@linux named]# systemctl restart named
[root@linux named]# vi /etc/resolv.conf
nameserver 192.168.130.128 #添加服务器的IP地址
[root@linux named]# vi /etc/hosts
192.168.130.128 mail.bk.com #添加服务器的IP地址
4.postfix配置
[root@linux ~]# vi /etc/postfix/main.cf #该文件为postfix的主配置文件
myhostname = mail.bk.com #75，邮件主机名
mydomain = bk.com #83，邮件域名
myorigin = $mydomain #99，发件人所在的域名，如@bk.com
inet_interfaces = all #116，监听的网络接口
inet_protocols = all #119，协议ipv4/ipv6
mydestination = $myhostname,$mydomain #164，接收邮件时收件人的域名
mynetworks =0.0.0.0/0 #264，网络
relay_domains = $mydestination #296，转发的域
home_mailbox = Maildir/ #419，采用系统用户的话，邮件箱为用户家目录下
#postfix 基于cyrus-sasl认证项
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions =
permit_sasl_authenticated,reject_unauth_destination,permit_mynetworks
smtpd_client_restrictions = permit_sasl_authenticated
5.Sasl2配置
[root@linux ~]# vi /etc/sysconfig/saslauthd
MECH=shadow #7，指定以本地系统用户名认证
[root@linux ~]# touch /usr/lib64/sasl2/smtpd.conf #创建SMTP认证的配置文件，此文件为64bit操作系统配置文件，32bit操作系统该文件位于/usr/lib/目录下
[root@linux ~]# vi /usr/lib64/sasl2/smtpd.conf
1 pwcheck_method: saslauthd
2 mech_list: PLAIN LOGIN
3 log_level:3
6.Dovecot配置
[root@linux ~]# vi /etc/dovecot/dovecot.conf
protocols = imap pop3 lmtp #24，使用协议
listen = * #31，*监听协议ipv4
[roo@linux ~]# vi /etc/dovecot/conf.d/10-auth.conf
disable_plaintext_auth = no #10
auth_mechanisms = plain #100
[root@linux ~]# vi /etc/dovecot/conf.d/10-mail.conf
mail_location = maildir:~/Maildir #24
[root@linux ~]# vi /etc/dovecot/conf.d/10-ssl.conf
ssl = no #8
7.启动服务
[root@linux ~]# systemctl start postfix && systemctl enable postfix
[root@linux ~]# systemctl start dovecot && systemctl enable dovecot
Created symlink from /etc/systemd/system/multi-user.target.wants/dovecot.service to /usr/lib/systemd/system/dovecot.service.
[root@linux ~]# systemctl start saslauthd && systemctl enable saslauthd
Created symlink from /etc/systemd/system/multi-user.target.wants/saslauthd.service to /usr/lib/systemd/system/saslauthd.service.
8.创建用户，方便测试
[root@linux ~]# useradd alice
[root@linux ~]# echo 'alice' | passwd --stdin alice
Changing password for user alice.
passwd: all authentication tokens updated successfully.
[root@linux ~]# useradd tom
[root@linux ~]# echo 'tom' | passwd --stdin tom
Changing password for user tom.
passwd: all authentication tokens updated successfully.
9.使用 telnet 工具进行发信、收信测试
[root@linux ~]# yum install telnet -y
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
Resolving Dependencies
--> Running transaction check
---> Package telnet.x86_64 1:0.17-64.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
==================================================================================
Package Arch Version Repository Size
==================================================================================
Installing:
telnet x86_64 1:0.17-64.el7 c7 64 k
Transaction Summary
==================================================================================
Install 1 Package
Total download size: 64 k
Installed size: 113 k
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : 1:telnet-0.17-64.el7.x86_64 1/1
Verifying : 1:telnet-0.17-64.el7.x86_64 1/1
Installed:
telnet.x86_64 1:0.17-64.el7
Complete!
#使用telnet工具测试
[root@linux ~]# telnet localhost 25
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 mail.bk.com ESMTP Postfix
HELO localhost
250 mail.bk.com
MAIL FROM:[email protected]
250 2.1.0 Ok
RCPT TO:[email protected]
250 2.1.5 Ok
DATA
354 End data with .
Subject:Test Mail
HELLO!
This is test mail!
.
250 2.0.0 Ok: queued as ADCFC6078DD2
QUIT
221 2.0.0 Bye
Connection closed by foreign host.
#刚才发送的信件就到了用户的Maildir目录下
[root@linux ~]# ls /home/tom/Maildir/new/
1543926902.V803I6078e34M85822.linux
[root@linux ~]# cat /home/tom/Maildir/new/1543926902.V803I6078e34M85822.linux
Return-Path:
X-Original-To: [email protected]
Delivered-To: [email protected]
Received: from localhost (localhost [IPv6:::1])
by mail.bk.com (Postfix) with SMTP id ADCFC6078DD2
for ; Tue, 4 Dec 2018 20:34:27 +0800 (CST)
Subject:Test Mail
Message-Id: <[email protected]>
Date: Tue, 4 Dec 2018 20:34:27 +0800 (CST)
From: [email protected]
HELLO!
This is test mail!
#收信测试
[root@linux ~]# telnet localhost 110
Trying ::1...
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready.
USER tom
+OK
PASS tom
+OK Logged in.
LIST
+OK 1 messages:
1 411
.
RETR 1
+OK 411 octets
Return-Path:
X-Original-To: [email protected]
Delivered-To: [email protected]
Received: from localhost (localhost [IPv6:::1])
by mail.bk.com (Postfix) with SMTP id ADCFC6078DD2
for ; Tue, 4 Dec 2018 20:34:27 +0800 (CST)
Subject:Test Mail
Message-Id: <[email protected]>
Date: Tue, 4 Dec 2018 20:34:27 +0800 (CST)
From: [email protected]
HELLO!
This is test mail!
.
quit
+OK Logging out.
Connection closed by foreign host.
10.使用Windows下的Foxmail软件进行发信收信测试
登陆新建的用户alice和tom，进行收发测试。
在用户tom下发送邮件给alice进行测试
在alice用户右键，选择收取
收件箱就会出现一封未读邮件
收发测试成功，至此自己的邮件服务系统配置完成
