To limit the delivery of incoming messages in PostFix to EuropeanMX servers, please follow the steps below.
Create a file /etc/postfix/access and add the following content:
Execute the following command:
Add the following content to the /etc/postfix/main.cf file
smtpd_client_restrictions = check_client_access hash:/etc/postfix/access, permit_mynetworks, reject
Or if you have already defined "smtpd_client_restrictions", add the following at the beginning of your definition and replace "permit" with "reject" at the end:
Add the following content to the /etc/postfix/main.cf file:
smtpd_restriction_classes = EuropeanMX
EuropeanMX = check_client_access hash:/etc/postfix/EuropeanMX, reject
smtpd_recipient_restrictions = check_recipient_access hash:/etc/postfix/protected_destinations, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
Create the file /etc/postfix/EuropeanMX with the following content:
If you also send and receive internal messages, then you must also add the localhost and localdomain to the file in the following format
Create the file /etc/postfix/protected_destinations and add the domain(s) you want to restrict in the following format:
Postmap both files.
Restart PostFix in order to apply the changes.