Tomas Macek:
> Hello, our system is sometimes under attack of spammers using
> "NOTIFY=SUCCESS" param in "rcpt to: " header. And because of a random From
> address, the DSN message obviously goes to an nonexistent server
> or user.
>
> I've read the "Restricting the scope of "success" notifications" topic at
> http://www.postfix.org/DSN_README.html#scope and I'd like to ask you about
> some details:
>
> 1) if I turn off the DSN for the networks outside of $mynetwork, do I
> understand it well, that we will not send them (to the outside world) any
> more DSNs with "user over quota" or "access denied"?
> We won't be sending anything probably in that case, just asking to be
> sure.
DSN is an optional extension of SMTP. With DSN turned off, the SMTP
protocol requires that the sender gets a non-delivery notification.
> 2) how much is it normal to turn off the DSN for outside world? What is
> your settings?
There are still MTAs that don't implement DSN, such as exim and
qmail.
Wietse
