How do I make Postfix to reject all mails if the client is not authenticated and to sender is @mydomain? Is the an easy way to do this?
Max
Your main.cf should contain this line:
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated,
reject_unauth_destination, reject_unlisted_recipient, permit
But make sure that the "client" is not in the network defined by mynetworks=
. Otherwise it will bypass the authentication test.