Exchange auto-forwarding email to remote domains must be disabled or restricted.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-228356 | EX16-MB-000030 | SV-228356r879533_rule | CCI-001368 | medium |
| Description | ||||
| Attackers can use automated messages to determine whether a user account is active, in the office, traveling, and so on. An attacker might use this information to conduct future attacks. Verify Automatic Forwards to remote domains are disabled, except for enterprise mail that must be restricted to forward only to .mil and .gov. domains. Before enabling this setting, configure a remote domain. | ||||
| STIG | Date | |||
| Microsoft Exchange 2016 Mailbox Server Security Technical Implementation Guide | 2023-12-18 | |||
Details
Check Text (C-228356r879533_chk)
Note: Requirement is not applicable on classified or completely closed networks.
Non-Enterprise Mail Check Content:
Open the Exchange Management Shell and enter the following command:
Get-RemoteDomain | Select Identity, AutoForwardEnabled
If the value of AutoForwardEnabled is not set to "False", this is a finding.
Enterprise Mail Check Content:
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.
Fix Text (F-30574r496865_fix)
Non-Enterprise Mail Fix Text:
Open the Exchange Management Shell and enter the following command:
Set-RemoteDomain -Identity <'IdentityName'> -AutoForwardEnabled $false
Note: The <IdentityName> value must be in single quotes.
Enterprise Mail Fix Text:
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 single quotes.