阿里云Centos7.3实践：搭建Sendmail服务器和配置

*以服务器地址120.79.254.2为例，服务器具体地址数值仅为示范所需，并非真实所用地址，如有冒犯，请联系更改。

1. 切换权限

sudo su root

2.安装DNS服务器软件包

yum install bind -y

yum install bind-libs -y

3.配置/etc/named.conf文件

vim /etc/named.conf

修改：

listen-on port 53 { any; };

allow-query { any; };

增加：

zone "uc-knight.top" IN{
type master;
file "uc-knight.top.zone";
};

zone "254.79.120.in-addr.arpa" IN{
type master;
file "254.79.120.zone";
};

4.配置 /var/named/uc-knight.top.zone 文件

vim /var/named/uc-knight.top.zone

$ttl 600

@ IN SOA lance.uc-knight.top. lance.www.uc-knight.top.(
2018060601 10800 3600 604800 38400 )
; Serial Refresh Retry Expire MinumumTTL
; Serial<2^32 Refresh>=Retry*2 Refresh+Retry<Expire
; Expire>=Retry*10
@ IN NS lance.uc-knight.top.
lance.uc-knight.top. IN A 120.79.254.2
@ IN MX 5 www.uc-knight.top.
www.uc-knight.top. IN A 120.79.254.2

5.配置 /var/named/254.79.120.zone 文件

vim /var/named/254.79.120.zone

$ttl 600
@ IN SOA lance.uc-knight.top. lance.www.uc-knight.top.(
2018060601 10800 3600 604800 38400 )
; Serial Refresh Retry Expire MinumumTTL
; Serial<2^32 Refresh>=Retry*2 Refresh+Retry<Expire
; Expire>=Retry*10
@ IN NS lance.uc-knight.top.
2 IN PTR lance.uc-knight.top.

6.启动named服务，并设为开机自启

systemctl start named

systemctl enable named

*7.DNS客户端配置（注意不是服务器端）

Linux: yum install bind-utils -y 然后编辑 vim /etc/resolv.conf

本例中为 nameserver 120.79.254.2

Windows: 本地连接/网络适配器-ipv4协议-手动配置输入dns地址

本例中为使用下面的DNS服务器地址- 120.79.254.2

**额外小内容：web服务器配置（基于完成以上DNS配置步骤）

a.安装web服务器软件包

yum install httpd -y

yum install httpd-tools -y

yum install http-manual -y

b.修改/etc/httpd/conf/httpd.conf 文件

vim /etc/httpd/conf/httpd.conf

修改以下内容

ServerAdmin [email protected]

ServerName www.uc-knight.top

c.将网页保存到/var/www/html目录中

本例使用echo命令生成index.html文件

echo "Welcome to uc-knight.top! " >/var/www/html/index.html

d.启动httpd服务，设为开机自启

systemctl start httpd

systemctl enable httpd

8.安装Sendmail服务器软件包(sendmail, sendmail-cf, procmail, m4)

yum install sendmail -y

yum install sendmail-cf -y

9.验证邮件交换器设置(通过配置好DNS的客户端，即完成了执行第7点的客户端)

nslookup -q=mx uc-knight.top

输出为：

Server: 120.79.254.2
Address: 120.79.254.2#53

uc-knight.top mail exchanger = 5 www.uc-knight.top.

10.配置 /etc/mail/sendmail.mc 文件

vim /etc/mail/sendmail.mc

修改：

dnl # DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

LOCAL_DOMAIN(`uc-knight.top')dnl

11.使用m4进行重定向/etc/mail/sendmail.cf

m4 /etc/mail/sendmail.mc >/etc/mail/sendmail.cf

12.vim /etc/mail/local-host-names

增加：

uc-knight.top <--域

www.uc-knight.top <--邮件主机名

13.vim /etc/hosts

增加：

120.79.254.2 lance www.uc-knight.top

服务器ip地址；主机名；邮箱主机名

**.修改主机名（静态瞬态灵活主机名同时修改）

hostnamectl set-hostname <hostname>

**查询主机名 hostname -f

或 vim /etc/hostname

*14.vim /etc/mail/access

120.79.254 RELAY
uc-knight.top RELAY

修改后重定向:

makemap hash /etc/mail/access.db </etc/mail/access

*15.编辑/etc/aliases文件

编辑后使用newaliases生成/etc/aliases.db数据库

16.运行sendmail服务，设置开机自启

systemctl start sendmail

systemctl enable sendmail

*可使用 systemctl status sendmail 查看是否已启动

*可使用 systemctl status sendmail -l 查看服务具体启动情况

*可使用 systemctl is-enabled sendmail 查询是否已设置为开机启动

17.安装dovecot软件包

yum install dovecot -y

18.vim /etc/dovecot/dovecot.conf

修改：

protocols = imap pop3 lmtp

listen = *

base_dir = /var/run/dovecot/

19.运行dovecot服务，设为开机自启

systemctl start dovecot

systemctl enable dovecot

开始测试在配置好dns的客户端上远程登陆pop3端口110

*SMTP 端口 TCP 25

*POP3 端口 TCP 110

*IMAP 端口 TCP 143

telnet 120.79.254.2 110

user test

pass test

(用户自己在系统中添加)

问题一：输入user test 回车后出现

-ERR [AUTH] Plaintext authentication disallowed on non-secure (SSL/TLS) connections.

解决：

vim /etc/dovecot/conf.d/10-auth.conf

修改

disable_plaintext_auth = no

vim /etc/dovecot/conf.d/10-ssl.conf

修改

ssl = no

重启dovecot服务

systemctl restart dovecot

问题二：修改问题一后，输入pass test，出现

-ERR [SYS/TEMP] Internal error occurred. Refer to server log for more information.

Connection closed by foreign host.

使用命令查看log

tail /var/log/maillog

Jun 6 23:43:29 iz6yiqbo5vklydz dovecot: pop3(test): Error: user test: Initialization failed: Namespace '': Mail storage autodetection failed with home=/home/test

Jun 6 23:43:29 iz6yiqbo5vklydz dovecot: pop3(test): Error: Invalid user settings. Refer to server log for more information.

解决： vim /etc/dovecot/conf.d/10-mail.conf

设置mail_location参数

mail_location = mbox:~/mail:INBOX=/var/mail/%u

问题三：接着修改完问题二后，继续登录，出现

-ERR [SYS/PERM] Permission denied
Connection closed by foreign host.

查看日志 tail /var/log/maillog

Error: chown(/home/test/mail/.imap, group=12(mail)) failed: Operation not permitted (egid=1002(test), group based on /var/mail/test - see http://wiki2.dovecot.org/Errors/ChgrpNoPerm)
Jun 6 23:51:12 iz6yiqbo5vklydz dovecot: pop3(test): Error: Couldn't open INBOX: Permission denied
Jun 6 23:51:12 iz6yiqbo5vklydz dovecot: pop3(test): Couldn't open INBOX top=0/0, retr=0/0, del=0/0, size=0

解决方案

更改权限 chmod 0600 /var/mail/* (或者权限改为777等)

本例中为test用户故命令为 chmod 0600 /var/mail/test

**使用命令查看日志文件

cat /var/log/maillog

tail /var/log/maillog

**不要用root用户远程登录邮箱服务器