How can I implement this in the Postfix SMTP server? For certain client IP addresses no authentication is required and the EHLO response should not advertise the AUTH option.
For a second set of client IP addresses authentication is required and the EHLO response should advertise AUTH PLAIN. For a third set of client IP addresses authentication is required and the EHLO response should advertise AUTH LOGIN. Clients in the third set must not be able to authenticate using the credentials defined for the second set, and vice versa. Rob