Configure Incoming Filtering with Postfix

  1. Create a file /etc/postfix/access with the content:

  3. Execute:
  4. postmap /etc/postfix/access

  5. Add the following to /etc/postfix/
  6. smtpd_client_restrictions = check_client_access hash:/etc/postfix/access, permit_mynetworks, reject

  7. Or, if you already have smtpd_client_restrictions defined, insert :
  8. "check_client_access hash:/etc/postfix/access"

    ... at the beginning of your definition, and replace permit with reject and the end of definition.

  9. Restart Postfix:
  10. /etc/init.d/postfix restart

Per domain setup

It's also possible with Postfix to configure the MTA to only allow connections from the Spam Experts servers for specific protected domains:

  1. Add this to the
  2. smtpd_restriction_classes = Spam Experts
    Spam Experts = check_client_access hash:/etc/postfix/Spam Experts, reject
    smtpd_recipient_restrictions = check_recipient_access hash:/etc/postfix/protected_destinations, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination

  3. Create the following file:
  4. /etc/postfix/Spam Experts

  5. with the following content:
  6. OK

    If you send or receive any internal mail, you will need to also add your domain, localhost and the local domain in the following format:
    domain.example OK
    localhost OK
    localdomain OK

  7. Create the following file:
  8. /etc/postfix/protected_destinations

  9. Add the domains that you want to configure:
  10. Spam Experts

  11. Postmap both files.
  12. Restart Postfix.

Local Cloud

Replace with your servers root hostname.