以下的文章主要讲述的是Postfix+Cyrus-SASL+MySQL数据库投递经过验证的邮件正确设置的实际操作步骤，就算它是要投到本地域的邮件或来自本地局域网的邮件都要通过验证，否则就不让过。main.cf 这一段要如何修改呢？

mynetworks_style=host

mynetworks = 168.100.189.0/28, 127.0.0.0/8

定义你的服务器IP

#====================SASL===================== 
smtpd_sasl_auth_enable=yes
smtpd_sasl_security_clients=noanonymous
broken_sasl_auth_clients=yes
smtpd_delay_reject=yes
smtpd_recipient_restrictions=permit_sasl_authenticated
reject_rbl_clientopm.blitzed.org 
reject_rbl_clientlist.dsbl.org 
reject_rbl_clientbl.spamcop.net 
reject_rbl_clientsbl-xbl.spamhaus.org 
reject_rbl_clientcbl.anti-spam.org.cn 
reject_rbl_clientcdl.anti-spam.org.cn 
reject_rbl_clientcblplus.anti-spam.org.cn 
reject_invalid_hostname 
reject_unknown_sender_domain 
reject_non_fqdn_sender 
reject_non_fqdn_recipient 
reject_unknown_recipient_domain 
reject_unauth_pipelining 
reject_unauth_destination 
permit_mynetworks 
check_recipient_maps 
smtpd_client_restrictions=permit_sasl_authenticated
smtpd_helo_restrictions=reject_invalid_hostname
smtpd_sender_restrictions=permit_sasl_authenticated
reject_non_fqdn_sender 
reject_unknown_sender_domain 
reject_sender_login_mismatch 
smtpd_sasl_authenticated_header=yes
smtpd_helo_required=yes