Exchange must not send automated replies to remote domains.

From Microsoft Exchange 2016 Mailbox Server Security Technical Implementation Guide

Associated with: CCI-001308

SV-95417r1_rule Exchange must not send automated replies to remote domains.

Vulnerability discussion

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.

Check content

Open the Exchange Management Shell and enter the following command: Get-RemoteDomain | Select Name, Identity, AutoReplyEnabled If the value of "AutoReplyEnabled" is not set to "False", this is a finding.

Fix text

Open the Exchange Management Shell and enter the following command: Set-RemoteDomain -Identity <'IdentityName'> -AutoReplyEnabled $false Note: The value must be in single quotes.

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