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

Exchange auto-forwarding email to remote domains must be disabled or restricted.

DISA Rule

SV-259651r960801_rule

Vulnerability Number

V-259651

Group Title

SRG-APP-000038

Rule Version

EX19-MB-000021

Severity

CAT II

CCI(s)

• CCI-001368 - Enforce approved authorizations for controlling the flow of information within the system based on organization-defined information flow control policies.

Weight

10

Fix Recommendation

For Non-Enterprise Mail:

Open the Exchange Management Shell and enter the following command:

Set-RemoteDomain -Identity <'IdentityName'> -AutoForwardEnabled $false

Note: The <IdentityName> value must be in quotes.

For Enterprise Mail:

New-RemoteDomain -Name <NewRemoteDomainName> -DomainName <SMTP Address>

Note: <NewRemoteDomainName> must either be a .mil or .gov domain.

Set-RemoteDomain -Identity <'RemoteDomainIdentity'> -AutoForwardEnabled $true

Note: The <RemoteDomainIdentity> value must be in quotes.

Check Contents

Note: This requirement is not applicable on classified or completely closed networks.

For Non-Enterprise Mail:

Open the Exchange Management Shell and enter the following command:

Get-RemoteDomain | Select-Object -Property Identity, AutoForwardEnabled

If the value of AutoForwardEnabled is not set to "False", this is a finding.

For Enterprise Mail:

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

and

In the Exchange Management Shell, enter the following command:

Get-RemoteDomain

If the value of "RemoteDomain" is not set to ".mil" and/or ".gov" domain(s), this is a finding.

Vulnerability Number

V-259651

Documentable

False

Rule Version

EX19-MB-000021

Severity Override Guidance

Note: This requirement is not applicable on classified or completely closed networks.

For Non-Enterprise Mail:

Open the Exchange Management Shell and enter the following command:

Get-RemoteDomain | Select-Object -Property Identity, AutoForwardEnabled

If the value of AutoForwardEnabled is not set to "False", this is a finding.

For Enterprise Mail:

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

and

In the Exchange Management Shell, enter the following command:

Get-RemoteDomain

If the value of "RemoteDomain" is not set to ".mil" and/or ".gov" domain(s), this is a finding.

Check Content Reference

M

Target Key

5580