Auditing Microsoft Exchange Servers

Exchange must not send automated replies 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. 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.

Open the Exchange Management Shell and enter the following command:

Set-RemoteDomain -Identity -AutoReplyEnabled $false

Note: The value must be in single quotes.

Note: Automated replies to enterprise sites are allowed.
Open the Exchange Management Shell and enter the following command:

Get-RemoteDomain | Select Name, Identity, AutoReplyEnabled
If the value of “AutoReplyEnabled” is set to “True” and is configured to only Reply to enterprise domain sites, this is not a finding.

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

SI-8 (2)