Information
Exchange must not send automated replies to remote domains.
GROUP ID: V-259692
RULE ID: SV-259692r961161
Attackers can use automated messages to determine whether a user account is active, in the office, traveling, and so on. An attacker might use this information to conduct future attacks. Remote users will not receive automated 'Out of Office' delivery reports. This setting can be used to determine if all the servers in the organization can send 'Out of Office' messages.
Solution
Open the Exchange Management Shell and enter the following command:
Set-RemoteDomain -Identity <'IdentityName'> -AutoReplyEnabled $false
Note: The <IdentityName> value must be in quotes.