Who knows how to configure KSMG with Exchange?

Question

Mail server

Good evening.
There was a bunch of MS Exchange 2010 + OFT. The first is the mail server and the second is the anti-spam. Decided to replace OFT with Kaspersky Security Mail Gateway. It receives and filters mail fine, but I can't send mail. Writes the following: Unable Relay. I understand that the problem is obviously in the authentication on the Exchange server, but Kaspersky is on the allowed network and is registered as a relay on the Exchange.
There is an assumption that it is necessary to configure authentication on Exchange, but is it really impossible without it? The fact is that there is no SSH password to configure it.

Answer 1

It seems that they even have documentation in Russian:
From your post it is not clear how you have it built into the system. Who writes Unable Relay...

Answer 2

There is an opinion that you need to allow your mail server to receive mail from the relay server (it's trite to add its SP to the CAS)
You don't need any authorization for the relay.
It works on the principle - received mail, checked, determined to whom (domain), sent to the SP of the mail server to which this domain is assigned.