The Exchange Sender Reputation filter must be enabled.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-259614	SRG-APP-000261	EX19-ED-000128	SV-259614r961161_rule	2024-12-06	2

Description
By performing filtering at the perimeter, up to 90 percent of spam, malware, and other undesirable messages are eliminated from the message stream rather than admitting them into the mail server environment. Sender Reputation is anti-spam functionality that blocks messages according to many characteristics of the sender. Sender Reputation relies on persisted data about the sender to determine what action, if any, to take on an inbound message. This setting enables the Sender Reputation function.

Description

By performing filtering at the perimeter, up to 90 percent of spam, malware, and other undesirable messages are eliminated from the message stream rather than admitting them into the mail server environment. Sender Reputation is anti-spam functionality that blocks messages according to many characteristics of the sender. Sender Reputation relies on persisted data about the sender to determine what action, if any, to take on an inbound message. This setting enables the Sender Reputation function.

ℹ️ Check
Note: If third-party anti-spam product is being used, the anti-spam product must be configured to meet the requirement. Additionally, the default value for "Sender Reputation" is "True" for "Enabled". Open the Exchange Management Shell and enter the following command: Get-SenderReputationConfig \| Select-Object -Property Name, Enabled If the value of "Enabled" is not set to "True", this is a finding.

ℹ️ Check

Note: If third-party anti-spam product is being used, the anti-spam product must be configured to meet the requirement. Additionally, the default value for "Sender Reputation" is "True" for "Enabled". Open the Exchange Management Shell and enter the following command: Get-SenderReputationConfig | Select-Object -Property Name, Enabled If the value of "Enabled" is not set to "True", this is a finding.

✔️ Fix
Open the Exchange Management Shell and enter the following command: Set-SenderReputationConfig -Enabled $true