参考http://wiki.centos.org/HowTos/postfix和http://wiki.centos.org/HowTos/postfix_sasl和http://technet.microsoft.com/en-us/library/aa995718%28EXCHG.65%29.aspx
安装所需软件包:
yum install postfix dovecot system-switch-mail
修改之前的postfix的配置:
[root@localhost postfix]# grep -v '^#' /etc/postfix/main.cf | grep .
