PS：使用时需要注意把域名替换成自己的域名，我这里的域名是 ken.paipaibo.net
脚本正文：
#!/bin/bash
for num in {1..20};do
useradd ken$num
echo "douhap123" |passwd --stdin ken$num
done
yum -y install ca-certificates yum-fastestmirror vim
rpm -ivh http://mirrors.sohu.com/fedora-epel/6/\
x86_64/epel-release-6-8.noarch.rpm
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-6
sed -i '3s/^#//' /etc/yum.repos.d/epel.repo
sed -i '4s/^/#/' /etc/yum.repos.d/epel.repo
yum -y install postfix cyrus* opendkim
cd /etc/postfix
postconf -n > main.cf.test
mv main.cf main.cf.bak
mv main.cf.test main.cf
sed -i '9s/localhost/all/' main.cf
echo "
mydomain = ken.paipaibo.net
myhostname = ken.paipaibo.net
mynetworks = 192.168.0.0/24,127.0.0.0/8
message_size_limit = 5242880
mailbox_size_limit = 5242880
show_user_unknown_table_name = no
bounce_queue_lifetime = 1d
maximal_queue_lifetime = 1d
smtpd_recipient_restrictions =
permit_mynetworks,
permit_sasl_authenticated,
reject_non_fqdn_hostname,
reject_non_fqdn_sender,
reject_non_fqdn_recipient,
reject_unauth_destination,
reject_unauth_pipelining,
reject_invalid_hostname,
permit_sasl_authenticated,
reject_unauth_destination,
smtpd_sender_restrictions =
permit_mynetworks,
reject_unauthenticated_sender_login_mismatch,
smtpd_sender_login_maps =
broken_sasl_auth_clients = yes
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = $myhostname
smtpd_sasl_security_options = noanonymous
smtpd_milters = inet:localhost:8891
non_smtpd_milters = inet:localhost:8891
milter_protocol = 2
milter_default_action = accept
" >> main.cf
echo -e "\n"
sed -i '39s/v/vs/' /etc/opendkim.conf
echo "Domain ken.paipaibo.net" >> /etc/opendkim.conf
echo "default._domainkey.ken.paipaibo.net \
ken.paipaibo.net:default:/etc/opendkim/keys/\
default.private" >> /etc/opendkim/KeyTable
echo "*@ken.paipaibo.net default._domainkey.\
ken.paipaibo.net" >> /etc/opendkim/SigningTable
cd /etc/opendkim/keys
opendkim-genkey -r -d ken.paipaibo.net
chown opendkim.opendkim default.private
cat default.txt
echo -e "\n"
echo "0 */5 * * * root postsuper -d \
ALL deferred" >> /etc/crontab
echo "0 */10 * * * root rm -rf \
/var/log/*-20*" >> /etc/crontab
echo "0 */10 * * * root echo ''>/var/log/maillog"\
>> /etc/crontab
echo "0 */10 * * * root echo ''>/var/log/btmp"\
>> /etc/crontab
echo "0 */10 * * * root echo ''>/var/spool/mail/root"\
>> /etc/crontab
echo "The Postfix mail installing is finished"
/etc/init.d/postfix restart
/etc/init.d/saslauthd restart
/etc/init.d/iptables stop
setenforce 0
/etc/init.d/opendkim restart
chkconfig postfix on
chkconfig saslauthd on
chkconfig iptables off
chkconfig opendkim on
echo OK