Hi i have mail server based on postfix ,courier and mysql as DB for mail boxes.running on ubuntu server i am new on in this so i have some quistions: how can i allo /prevent using my smtp relay as smarthost. examle: my friend has mail server based on exchange,he want to use my smtp relay as smarthost in exchnge. so i created for him mail box in my mail server(username and pass),so he can use it in exchange ? and how can i prevent it?that nobody can use username and pass from my mail server as "smarthost" in other mail system,just if i allowed it thanks a lot)
