Exchange must have accepted domains configured.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-259579	EX19-ED-000017	SV-259579r942051_rule		Medium

Description
Exchange may be configured to accept email for multiple domain names. This setting identifies the domains for which the server will accept mail. This check verifies the email server is not accepting email for unauthorized domains.

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

Details

Check Text ( C-63318r942049_chk )
Review the Email Domain Security Plan (EDSP). Determine the Accepted Domain values. Open the Exchange Management Shell and enter the following command: Get-AcceptedDomain \| Select-Object -Property Name, DomainName, Identity, Default If the value of "Default" is not set to "True", this is a finding. or If the "Default" value for "AcceptedDomains" is set to another value other than "True" and has signoff and risk acceptance in the EDSP, this is not a finding.

Check Text ( C-63318r942049_chk )

Review the Email Domain Security Plan (EDSP).

Determine the Accepted Domain values.

Open the Exchange Management Shell and enter the following command:

Get-AcceptedDomain | Select-Object -Property Name, DomainName, Identity, Default

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

or

If the "Default" value for "AcceptedDomains" is set to another value other than "True" and has signoff and risk acceptance in the EDSP, this is not a finding.

Fix Text (F-63226r942050_fix)
Update the EDSP. Open the Exchange Management Shell and enter the following command: Set-AcceptedDomain -Identity <'IdentityName'> -MakeDefault $true Note: The value must be in quotes.