Wietse Venema:
> A brief example:
>
> /etc/postfix/sender_access:
> example.com reject Sender address requires authentication
> other.example reject Sender address requires authentication
>
> Do "postmap /etc/postfix/sender_access", then add this to main.cf:
>
> smtpd_sender_restrictions =
> permit_mynetworks
> permit_sasl_authenticated
> check_sender_access hash:/etc/postfix/sender_access
>
> With this, only senders in a trusted network, or authenticated
> senders, can do "MAIL FROM:<u...@example.com>" etc.
>
> This does not restrict the address in the From: message header.
BTW this means that you have to do your "telnet" tests from a
remote IP address!
Wietse
