Have a problem that I can't find a solution on.
I have a postfix configured ok, all local domain user accounts can send and recieve ok. The problem I have is that this postfix is located in a some sort of restricted environment and the policy is that a user is only allowed to send external mails to it's own account in the external domain and no one else in that external domain.
Is it possible to configure Postfix so that user1@localdomain can send to *@localdomain but only user1@externaldomain ?