I tried the following and it is working great.
What I need to know is how to allow some email accounts to send out emails with diffierent "From" compared to the login username. In other words, how to create exceptions to the rule.
check_sender_access hash:/etc/postfix/allowed_user with the contents like
Unfortunately it does not work.
Anyway to allow some email accounts to send out emails with different "From" compared to the auth login?