STIGQter: STIG Summary: Microsoft Exchange 2019 Mailbox Server Security Technical Implementation Guide Version: 2 Release: 3 Benchmark Date: 02 Jul 2025:

Exchange email-forwarding SMTP domains must be restricted.

DISA Rule

SV-259673r961128_rule

Vulnerability Number

V-259673

Group Title

SRG-APP-000231

Rule Version

EX19-MB-000117

Severity

CAT II

CCI(s)

• CCI-001199 - Protects the confidentiality and/or integrity of organization-defined information at rest.

Weight

10

Fix Recommendation

Update the EDSP to specify any accounts that have been authorized to have email auto-forwarded or verify that this information is documented by the organization.

For domains that are listed in the EDSP to allow AutoForwarding, open the Exchange Management Shell and enter the following command:

Set-RemoteDomain -Identity <RemoteDomainIdParameter> -AutoForwardEnabled $true

If the Remote Domain is NOT listed in the EDSP to allow for AutoForwarding, open the Exchange Management Shell and enter the following command:

Set-RemoteDomain -Identity [RemoteDomainIdentity] -AutoForwardingEnabled $false

Check Contents

Review the Email Domain Security Plan (EDSP) or document that contains this information.

Determine any accounts that have been authorized to have email auto-forwarded.

Note: If email auto-forwarding is not being used, this check is not applicable (NA).

Open the Exchange Management Shell and enter the following commands:

Get-RemoteDomain | Select Name, Identity, DomainName, AutoForwardEnabled |Format-List

If any domain for a user forwarding SMTP address is not documented in the EDSP, this is a finding.

Note: If no remote SMTP domain matching the mail-enabled user or contact that allows forwarding is configured for users identified with a forwarding address, this function will not work properly.

Vulnerability Number

V-259673

Documentable

False

Rule Version

EX19-MB-000117

Severity Override Guidance

Review the Email Domain Security Plan (EDSP) or document that contains this information.

Determine any accounts that have been authorized to have email auto-forwarded.

Note: If email auto-forwarding is not being used, this check is not applicable (NA).

Open the Exchange Management Shell and enter the following commands:

Get-RemoteDomain | Select Name, Identity, DomainName, AutoForwardEnabled |Format-List

If any domain for a user forwarding SMTP address is not documented in the EDSP, this is a finding.

Note: If no remote SMTP domain matching the mail-enabled user or contact that allows forwarding is configured for users identified with a forwarding address, this function will not work properly.

Check Content Reference

M

Target Key

5580