Exchange must not send delivery reports to remote domains.

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. Ensure that delivery reports to remote domains are disabled. Before enabling this setting, first configure a remote domain using the Exchange Management Console (EMC) or the New-RemoteDomain cmdlet.

Open the Exchange Management Shell and enter the following command:

Get-RemoteDomain | Select-Object -Property Identity, DeliveryReportEnabled

If the value of "DeliveryReportEnabled" is not set to "False", this is a finding.

Open the Exchange Management Shell and enter the following command:

Set-RemoteDomain -Identity <'IdentityName'> -DeliveryReportEnabled $false

Note: The <IdentityName> value must be in quotes.