vi /etc/postfix/main.cf
# Anti UCE ( Spam ) restrictions
#####################################################
disable_vrfy_command = yes
smtpd_delay_reject = yes
smtpd_helo_required = yes
# Check if the sending client (Server IP) is whitelisted or blacklisted
smtpd_client_restrictions = check_client_access hash:/etc/postfix/client_access
# Check during the client issue HELO command
#smtpd_helo_restrictions = check_helo_access hash:/etc/postfix/helo_access, reject_invalid_hostname
smtpd_helo_restrictions = check_helo_access hash:/etc/postfix/helo_access
# Determine if the individual sender can send or not to the server. Usefull to whitelist all those blacklisted email address
smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/sender_access, reject_non_fqdn_sender, reject_unknown_sender_domain
# Most important rule that defined the rule that is left out
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_non_fqdn_recipient, reject_unknown_recipient_domain,
reject_unverified_recipient, reject_unauth_destination
#This prevents the connecting client from pipelining SMTP commands
smtpd_data_restrictions = reject_unauth_pipelining
vi /etc/postfix/helo_access
#10.0.0.3 REJECT
#localhost REJECT
#mail.xxx.cn OK
#
# ACCESS(5)
localhost REJECT
service postfix restart ...
由于服务器拒绝收件人之一，无法发送邮件。被拒绝的电子邮件地址是“
exping@163.com”。 主题 '测试outlook', 帐户: 'mail.xxx.cn', 服务器: 'mail.xxx.cn', 协议: SMTP, 服务器响应: '554 <
exping@163.com>: Relay access denied', 端口: 25, 安全(SSL): 否, 服务器错误: 554, 错误号: 0x800CCC79
求问！
