Postfix Realy on Centos-6.2

Postfix Realy 

 

After configuring opsview monitoring server in production server i needed to send alert to all the admins and ops team now i need to configure postfix to configure as a open realy server so that it can send mail to gmail or other mail server.

1. Installing Postfix {uninstall sendmail}
# yum install postfix

2. Configuring

Basically, you need to create a password file so that Postfix can authenticate to Gmail's servers. You do this by creating a file named sasl_passwd in /etc/postfix. Replace smtp_user and smtp_passwd with their respective values.

# echo "smtp.gmail.com: 587 shashi.brain11@gmail.com:shashi_linux" > /etc/postfix/sasl_passwd

{ shashi.brain11@gmail.com this ID sending a alert other domain, like gmail.com, yahoo.com }

3. You then hash that file so that the password is not stored in clear text. This command will create a file named sasl_passwd.db in the /etc/postfix/ directory.

# postmap hash:/etc/postfix/sasl_passwd

4. After that is done, add these to the bottom of /etc/postfix/main.cf. This is assuming that your root certificates installed from openssl are located in /etc/pki/tls/certs/ca-bundle.crt.

smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
# Secure channel TLS with exact nexthop name match.
smtp_tls_security_level = secure
smtp_tls_mandatory_protocols = TLSv1
smtp_tls_mandatory_ciphers = high
smtp_tls_secure_cert_match = nexthop
smtp_tls_CAfile = /etc/pki/tls/certs/ca-bundle.crt
relayhost = smtp.gmail.com:587

5. After that is done, restart postfix:
# service postfix restart

6. Test Postfix-realy :

#echo "Test mail from postfix" | mail -s "Test Postfix" shashi11.linux@gmail.com

#tail -f /var/log/maillog