准备工作 搭建dns
yum install postfix
vi /etc/postfix/main.cf
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
mail_owner = postfix
myhostname = mail.abc.com
mydomain = abc.com
myorigin = $mydomain
inet_interfaces = all
inet_interfaces = all
inet_protocols = all
mydestination = $mydomain
local_recipient_maps =
unknown_local_recipient_reject_code = 550
mynetworks = 0.0.0.0/0
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
smtpd_banner = $myhostname ESMTP unknow
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.10.1/samples
readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES
原文：http://www.cnblogs.com/han1094/p/6394819.html