Sender Domain Restriction for Postfix Users

Sender Domain Restriction for Postfix Users : (outgoing)

Sometimes we flooded with huge spam mails changing the sender address. So it is very important for a administrator to stop the option for local users. Through the following process sender can send mail only from the allowed domain names as from address domain.

Step 1: Add the following line in "main.cf"

# vim /etc/postfix/main.cf

smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/mydomains, reject_unauth_destination

:wq!                 Save and Exit

 

Step 2: Create a file in postfix directory. 

vim /etc/postfix/mydomains 

mydomain1.com         OK 
mydomain2.com         OK

 :wq!                            Save and exit.

 
Step 3: postmap the file.

postmap /etc/postfix/mydomains

 

Step 4: Restart the service.

/etc/init.d/postfix restart

Now users@mydomain1.com / users@mydomain2.com can send mails using this MX.