摘自：https://www.cnblogs.com/yinzuopu/p/15504270.html
1. 前期准备：
主机：CentOS release 7.6.1810 (Core) #安装时选择邮件服务器
IP:192.168.71.108 #示例
本地yum源 #因为是内网，所以建议用镜像搭建本地yum源
2. 基础环境配置
关闭selinux：
sed –I ‘s/enforcing/disabled/g’ /etc/selinux/config
防火墙等配置：
firewall-cmd –add-port=’110/tcp’ –permanent
firewall-cmd –add-port=’25/tcp’ –permanent
或直接关闭防火墙，因为是内网，也不会有安全问题
systemctl start firewalld.service
主机名配置:
重启系统以使上述配置生效
shutdown -r now
3. Postfix安装与配置
3.1. 安装postfix
因为安装centos时选择的是邮件系统，所以检查是否自带postfix服务，如果没带则可通过本地yum源安装：yum -y insatll postfix --nogpgcheck
3.2. 配置postfix
[root@mail ~]# vim /etc/postfix/main.cf
- myhostname =mail.yzp.com #定义主机名
- mydomain =yzp.com #定义域名
- myorigin =$mydomain #定义组织域
- 我们需要在mydestination的值后面添加 $mydomain ,
- 如果不添加的话，收件人的地址会有问题，如果添加后，用户发送邮件直接会是xx@yzp.com
- 取消注释 #local_recipient_maps =
3.3. 启动和检查postfix
[root@mail ~]# systemctl start postfix.service
[root@mail ~]# systemctl enable postfix.service
[root@mail ~]# netstat -nltp
4. dovecot安装与配置
4.1. 安装dovecot
[root@mail ~]# yum -y install dovecot --nogpgcheck
4.2. 配置dovecot
接下来我们查看dovecot的默认配置文件
[root@mail ~]# cat /etc/dovecot/dovecot.conf
我们看见以下include可以包含的配置文件路径，在该路径下的*.conf文件都会生效
4.2.1. vim /etc/dovecot/dovecot.conf启用协议以下协议及监听
protocols = imap pop3 lmtp
#启用端口监听
listen = *,::
4.2.2. vim /etc/dovecot/conf.d/10-auth.conf设置如下参数
vim /etc/dovecot/conf.d/10-auth.conf
disable_plaintext_auth = no
auth_mechanisms = plain login
!include auth-system.conf.ext
4.2.3. vim /etc/dovecot/conf.d/10-ssl.conf禁用ssl认证
vim /etc/dovecot/conf.d/10-ssl.conf
ssl = no
4.2.4. vim /etc/dovecot/conf.d/10-logging.conf启用dovecot的日志
vim /etc/dovecot/conf.d/10-logging.conf
添加
info_log_path = /var/log/dovecot_info.log
debug_log_path = /var/log/dovecot_debug.log
4.3. 启动和检查dovecot
[root@mail ~]# systemctl start dovecot.service
[root@mail ~]# systemctl enable dovecot.service
[root@mail ~]# netstat -nltp | grep dovecot
5. 创建测试账户与测试邮件收发通信
5.1. 创建两个测试账户
[root@mail ~]# useradd test1
[root@mail ~]# passwd test1
[root@mail ~]# useradd test2
[root@mail ~]# passwd test2
5.2. 测试110端口：收邮件端口
[root@mail ~]# telnet 192.168.71.108 110
Trying 192.168.71.108...
Connected to 192.168.71.108.
Escape character is '^]'.
+OK [XCLIENT] Dovecot ready.
user test1
+OK
pass 111111
+OK Logged in.
-ERR [SYS/PERM] Permission denied
Connection closed by foreign host.
我们查看log
[root@mail ~]# cd /var/log/
[root@mail log]# tailf maillog
我们切换到刚才的用户：
[test1@mail ~]$ su - test1
密码：
[test2@mail ~]$ mkdir -p ~/mail/.imap/INBOX
[test1@mail ~]$ su - test2
密码：
[test2@mail ~]$ mkdir -p ~/mail/.imap/INBOX
再次测试110端口，发现测试通过了
[root@mail ~]# telnet 192.168.71.108 110
Trying 192.168.71.108...
Connected to 192.168.71.108.
Escape character is '^]'.
+OK [XCLIENT] Dovecot ready.
user test1
+OK
pass 111111
+OK Logged in.
quit
+OK Logging out.
Connection closed by foreign host.
5.3. 测试25端口：发邮件端口
[root@mail ~]# telnet 192.168.71.108 25
Trying 192.168.71.108...
Connected to 192.168.71.108.
Escape character is '^]'.
220 mail.yzp.com ESMTP unkown
mail from:test1@yzp.com
250 2.1.0 Ok
rcpt to:test2@yzp.com
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
.
250 2.0.0 Ok: queued as 338CE61533C9
quit
221 2.0.0 Bye
Connection closed by foreign host.
5.4. 测试上述查收上述test1发给test2的邮件
6. 同局域网内的windows电脑配置foxmail测试邮件收发
6.1. 配置新建账号
6.2. 互相收发邮件
收发测试通过，至此，环境搭建通过。
7. 检查邮件存储位置
[root@mail postfix]# cat /etc/dovecot/conf.d/10-mail.conf | grep mail_location
# path given in the mail_location setting.
# mail_location = maildir:~/Maildir
mail_location = mbox:~/mail:INBOX=/var/mail/%u
# mail_location = mbox:/var/mail/%d/%1n/%n:INDEX=/var/indexes/%d/%1n/%n
#mail_location =
# mail_location, which is also the default for it.
[root@mail postfix]# cd /var/mail/
