yum install postfix
rpm -e sendmail
alternatives --display mta
/usr/sbin/alternatives --set mta /usr/sbin/sendmail.postfix
vim /etc/postfix/main.cf
myhostname = mail.test.cn
mydomain = test.cn
myorigin = $mydomain
inet_interfaces = all
mydestination = $myhostname,$mydomain
mynetworks = 127.0.0.0/8
relay_domains =
home_mailbox = Maildir/
service postfix start
rpm -qa dovecot
yum -y install dovecot
vim /etc/dovecot.conf
protocols = imap imaps pop3 pop3s
service dovecot start
service saslauthd restart
postmap /etc/postfix/generic
参考：http://blog.csdn.net/ikscher/article/details/9084313
原文：http://www.cnblogs.com/112ba/p/6219325.html