题目：两个不同网段的邮件服务可以通过DNS解析互发邮件
DNS ：eth0 192.168.18.103
eth1 192.168.17.103
邮件服务器1： mail.vfast.com 192.168.18.104
邮件服务器2： mail.haha.com 192.168.17.106
DNS:
[root@localhost ~]# echo > 1 /proc/sys/net/ipv4/ip_forward
[root@localhost ~]# vim /etc/sysctl.conf
[root@localhost ~]# sysctl -p
net.ipv4.ip_forward = 1
net.ipv4.conf.default.rp_filter = 1
net.ipv4.conf.default.accept_source_route = 0
kernel.sysrq = 0
kernel.core_uses_pid = 1
net.ipv4.tcp_syncookies = 1
kernel.msgmnb = 65536
kernel.msgmax = 65536
kernel.shmmax = 4294967295
kernel.shmall = 268435456
[root@localhost ~]# service network restart
正在关闭接口 eth0： [确定]
正在关闭接口 eth1： [确定]
关闭环回接口： [确定]
禁用 IPv4 包转送： net.ipv4.ip_forward = 0
[确定]
弹出环回接口： [确定]
弹出界面 eth0： [确定]
弹出界面 eth1： [确定]
[root@localhost ~]# yum install bind*
[root@localhost ~]# vim /var/named/chroot/etc/named.conf
options {
directory "/var/named";
};
zone "vfast.com"{
type master;
file "vfast.com.zone";
};
zone "haha.com"{
type master;
file "haha.com.zone";
};
[root@localhost ~]# cp /usr/share/doc/bind-9.3.6/sample/var/named/localhost.zone /var/named/chroot/var/named/vfast.com.zone
[root@localhost ~]# vim /var/named/chroot/var/named/vfast.com.zone
$TTL 86400
@ IN SOA @ root (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
vfast.com. IN NS mail.vfast.com.
mail.vfast.com. IN A 192.168.18.104
vfast.com. IN MX 10 mail.vfast.com.
haha.com. IN NS mail.haha.com.
mail.haha.com. IN A 192.168.17.106
mail.haha.com. IN MX 19 mail.haha.com.
[root@localhost ~]# cp /usr/share/doc/bind-9.3.6/sample/var/named/localhost.zone /var/named/chroot/var/named/haha.com.zone
[root@localhost ~]# vim /var/named/chroot/var/named/haha.com.zone
$TTL 86400
@ IN SOA @ root (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
vfast.com. IN NS mail.vfast.com.
mail.vfast.com. IN A 192.168.18.104
vfast.com. IN MX 10 mail.vfast.com.
haha.com. IN NS mail.haha.com.
mail.haha.com. IN A 192.168.17.106
haha.com. IN MX 10 mail.haha.com.
[root@localhost ~]# echo "" > /etc/hosts
[root@localhost ~]# cat /etc/hosts
[root@localhost ~]# service named restart
停止 named： [确定]
启动 named： [确定]
[root@localhost ~]# echo "" > /etc/resolv.conf
[root@localhost ~]# host mail.vfast.com
mail.vfast.com has address 192.168.18.104
[root@localhost ~]# host mail.vfast.com
mail.vfast.com has address 192.168.18.104
邮件服务器1：
[root@localhost ~]# route add default gw 192.168.18.103
[root@localhost ~]# service network restart
正在关闭接口 eth0： [确定]
关闭环回接口： [确定]
弹出环回接口： [确定]
弹出界面 eth0： [确定]
[root@localhost ~]# service sendmail status
sendmail 已停
[root@localhost ~]# chkconfig sendmail off
[root@localhost ~]# vim /etc/resolv.conf
nameserver 192.168.18.103
[root@localhost ~]# rpm -qa | grep postfix
postfix-2.3.3-2.1.el5_2
[root@localhost ~]# vim /etc/postfix/main.cf
myhostname = mail.vfast.com
mydomain = vfast.com
myorigin = $mydomain
inet_interfaces = all
mydestination = $myhostname, $mydomain,
mynetworks = 192.168.18.0/24, 192.168.17.0/24, 127.0.0.0/8
relay_domains = vfast.com, haha.com
mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp
末尾加：
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = ''
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
broken_sasl_auth_clients = yes
smtpd_client_restrictions = permit_sasl_authenticated
smtpd_sasl_security_options = noanonymous
[root@localhost ~]# service postfix restart
关闭 postfix： [失败]
启动 postfix： [确定]
安装dovecot：
[root@localhost ~]# yum install dovecot -y
修改配置文件：
[root@mail ~]# vim /etc/dovecot.conf
protocols = pop3 pop3s
protocol imap {
listen = *:10143
ssl_listen = *:10943
# ..
}
启动：
[root@mail ~]# /etc/init.d/dovecot start
启动 Dovecot Imap： [确定]
[root@localhost ~]# chkconfig dovecot on
[root@localhost ~]# yum install cyrus-imapd cyrus-imapd-devel -y
[root@localhost ~]# /etc/init.d/cyrus-imapd start
导入 cyrus-imapd 数据库： [确定]
启动 cyrus-imapd： [确定]
[root@localhost ~]# chkconfig cyrus-imapd on
[root@localhost ~]# service postfix restart
关闭 postfix： [确定]
启动 postfix： [确定]
[root@localhost ~]# telnet mail.haha.com 25
Trying 192.168.17.106...
Connected to mail.haha.com (192.168.17.106).
Escape character is '^]'.
220 mail.haha.com ESMTP Postfix
ehlo mail.haha.com
250-mail.haha.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
^]
telnet> quit
Connection closed.
[root@localhost ~]# vim /etc/sysconfig/saslauthd
MECH=shadow
[root@localhost ~]# service saslauthd restart
停止 saslauthd： [失败]
启动 saslauthd： [确定]
[root@localhost ~]# chkconfig saslauthd on
[root@localhost ~]# useradd abc
[root@localhost ~]# passwd abc
Changing password for user abc.
New UNIX password:
BAD PASSWORD: it is WAY too short
Retype new UNIX password:
passwd: all authentication tokens updated successfully.
[root@localhost ~]# testsaslauthd -u abc -p "abc"
0: OK "Success."
[root@localhost ~]# service postfix restart
关闭 postfix： [确定]
启动 postfix： [确定]
[root@localhost ~]# cyradm -u cyrus localhost
IMAP Password:
localhost.localdomain> cm user.abc
localhost.localdomain> quit
[root@localhost ~]# yum install squirrelmail -y
[root@localhost ~]# /usr/share/squirrelmail/config/conf.pl
修改默认的IMAP服务：d--->cryus--->
修改服务器设置：2--->1（设置域名）--->vfast.com---->3(选择邮件类型)--->2(smtp)---->r(进入主菜单)----4（设置区分大小写）----->5---->---y----r(返回)--->10(修改字符编码)----->1--->zh_CN--->2----->gb2312---->s---->q
邮件服务器2：
[root@localhost ~]# route add default gw 192.168.17.103
[root@localhost ~]# service network restart
正在关闭接口 eth0： [确定]
关闭环回接口： [确定]
弹出环回接口： [确定]
弹出界面 eth0： [确定]
[root@localhost ~]# service sendmail status
sendmail 已停
[root@localhost ~]# chkconfig sendmail off
[root@localhost ~]# vim /etc/resolv.conf
nameserver 192.168.17.103
[root@localhost ~]# yum install postfix -y
[root@localhost ~]# vim /etc/postfix/main.cf
myhostname = mail.haha.com
mydomain = haha.com
myorigin = $mydomain
inet_interfaces = all
mydestination = $myhostname, $mydomain,
mynetworks = 192.168.18.0/24, 192.168.17.0/24, 127.0.0.0/8
relay_domains = vfast.com, haha.com
mailbox_transport = lmtp:unix:/var/lib/imap/socket/lmtp
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = ''
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
broken_sasl_auth_clients = yes
smtpd_client_restrictions = permit_sasl_authenticated
smtpd_sasl_security_options = noanonymous
安装dovecot：
[root@localhost ~]# yum install dovecot -y
修改配置文件：
[root@mail ~]# vim /etc/dovecot.conf
protocols = pop3 pop3s
protocol imap {
listen = *:10143
ssl_listen = *:10943
# ..
}
启动：
[root@mail ~]# /etc/init.d/dovecot start
启动 Dovecot Imap： [确定]
[root@localhost ~]# chkconfig dovecot on
[root@localhost ~]# yum install cyrus-imapd cyrus-imapd-devel -y
[root@localhost ~]# /etc/init.d/cyrus-imapd start
导入 cyrus-imapd 数据库： [确定]
启动 cyrus-imapd： [确定]
[root@localhost ~]# chkconfig cyrus-imapd on
[root@localhost ~]# service postfix restart
关闭 postfix： [确定]
启动 postfix： [确定]
[root@localhost ~]# telnet mail.haha.com 25
Trying 192.168.17.106...
Connected to mail.haha.com (192.168.17.106).
Escape character is '^]'.
220 mail.haha.com ESMTP Postfix
ehlo mail.haha.com
250-mail.haha.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
^]
telnet> quit
Connection closed.
[root@localhost ~]# vim /etc/sysconfig/saslauthd
MECH=shadow
[root@localhost ~]# service saslauthd restart
停止 saslauthd： [失败]
启动 saslauthd： [确定]
[root@localhost ~]# chkconfig saslauthd on
[root@localhost ~]# useradd abc
[root@localhost ~]# passwd abc
Changing password for user abc.
New UNIX password:
BAD PASSWORD: it is WAY too short
Retype new UNIX password:
passwd: all authentication tokens updated successfully.
[root@localhost ~]# testsaslauthd -u abc -p "abc"
0: OK "Success."
[root@localhost ~]# service postfix restart
关闭 postfix： [确定]
启动 postfix： [确定]
[root@localhost ~]# cyradm -u cyrus localhost
IMAP Password:
localhost.localdomain> cm user.abc
localhost.localdomain> quit
[root@localhost ~]# yum install squirrelmail -y
[root@localhost ~]# /usr/share/squirrelmail/config/conf.pl
修改默认的IMAP服务：d--->cryus--->
修改服务器设置：2--->1（设置域名）--->vfast.com---->3(选择邮件类型)--->2(smtp)---->r(进入主菜单)----4（设置区分大小写）----->5---->---y----r(返回)--->10(修改字符编码)----->1--->zh_CN--->2----->gb2312---->s---->q
测试：在邮件服务器1上，用[email protected]给[email protected]发一封邮件，到邮件服务器2上查看，反之再回复一封，在查看