The Exchange Simple Mail Transfer Protocol (SMTP) Sender filter must be enabled.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-259625	EX19-ED-000139	SV-259625r942189_rule		Medium

Description
Email system availability depends in part on best practices strategies for setting tuning configurations. Careful tuning reduces the risk that system or network congestion will contribute to availability impacts. Filters that govern inbound email evaluation can significantly reduce spam, phishing, and spoofed emails. Filters for messages from blank senders, known spammers, or zero-day attack modifications must be enabled to be effective. Failure to enable the filter will result in no action taken. This setting should always be enabled.

Description

Email system availability depends in part on best practices strategies for setting tuning configurations. Careful tuning reduces the risk that system or network congestion will contribute to availability impacts. Filters that govern inbound email evaluation can significantly reduce spam, phishing, and spoofed emails. Filters for messages from blank senders, known spammers, or zero-day attack modifications must be enabled to be effective. Failure to enable the filter will result in no action taken. This setting should always be enabled.

STIG	Date
Microsoft Exchange 2019 Edge Server Security Technical Implementation Guide	2024-01-10

Details

Check Text ( C-63364r942187_chk )
This requirement is not applicable for SIPR enclaves. This requirement is not applicable if the organization subscribes to EEMSG or other similar DOD enterprise protections for email services. Open the Exchange Management Shell and enter the following command: Get-SenderFilterConfig \| Select-Object -Property Name, Enabled If the value of "Enabled" is not set to "True", this is a finding. Note: "Enabled" set to "True" is the default value.

Check Text ( C-63364r942187_chk )

This requirement is not applicable for SIPR enclaves.

This requirement is not applicable if the organization subscribes to EEMSG or other similar DOD enterprise protections for email services.

Open the Exchange Management Shell and enter the following command:

Get-SenderFilterConfig | Select-Object -Property Name, Enabled

If the value of "Enabled" is not set to "True", this is a finding.

Note: "Enabled" set to "True" is the default value.

Fix Text (F-63272r942188_fix)
Open the Exchange Management Shell and enter the following command: Set-SenderFilterConfig -Enabled $true