Configure A Postfix Relay Through Gmail On CentOS 7

參考：
https://devops.ionos.com/tutorials/configure-a-postfix-relay-through-gmail-on-centos-7/




yum -y install postfix cyrus-sasl-plain mailx

#systemctl restart postfix
#systemctl enable postfix



# Configure Postfix
 vi /etc/postfix/main.cf

#  必須修改
inet_interfaces = all

# 以下加入
relayhost = [smtp.gmail.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_tls_CAfile = /etc/ssl/certs/ca-bundle.crt
smtp_sasl_security_options = noanonymous
smtp_tls_security_level = encrypt
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# 修改密碼檔
vi /etc/postfix/sasl_passwd

[smtp.gmail.com]:587 username:password

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chown root:postfix /etc/postfix/sasl_passwd*
chmod 640 /etc/postfix/sasl_passwd*

systemctl reload postfix

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Test Relay

echo "This is a test." | mail -s "test message" cc.vbhsieh@gmail.com

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