postfix+mysql+dovecot
(也可以下载雷鸟进行收发邮件！！！）
服务器是192.168.0.254
实验的主机是192.168.0.119
(这个实验是在postfix+mysql的实验基础上做的！！！)
#setenforce 0(selinux)
# yum -y install dovecot dovecot-mysql
# vi /etc/dovecot/conf.d/10-mail.conf
mail_location = maildir:/home/vmail/%d/%n
# cp /etc/dovecot/conf.d/auth-sql.conf.ext /etc/dovecot/conf.d/auth-sql.conf
# cp /usr/share/doc/dovecot-2.0/example-config/dovecot-sql.conf.ext /etc/dovecot/
# vi /etc/dovecot/dovecot-sql.conf.ext
driver = mysql
default_pass_scheme = PLAIN
connect = host=localhost dbname=josion user=vmail password=vmail
password_query = \
  SELECT username, domain, password \
  FROM sunjunchao WHERE username = '%u'
user_query = \
  SELECT mailbox, 600 AS uid, 600 AS gid \
  FROM sunjunchao WHERE username = '%u'
# yum install telnet -y
# telnet localhost 110
Connected to localhost.
Escape character is '^]'.
+OK Dovecot ready. <19ca.1.4e74109f.ZuSZIv+SD1sYR9SPtvSUAg==@desktop35.example.com>
user josion@westos.org
+OK
pass josion
+OK Logged in.
list
+OK
（这样表示登录成功！）