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

Exchange internet-facing send connectors must specify a smart host.

DISA Rule

SV-259670r961101_rule

Vulnerability Number

V-259670

Group Title

SRG-APP-000213

Rule Version

EX19-MB-000106

Severity

CAT II

CCI(s)

• CCI-001178 - Provide additional data origin authentication artifacts along with the authoritative name resolution data the system returns in response to external name/address resolution queries.

Weight

10

Fix Recommendation

Open the Exchange Management Shell and enter the following command:

Set-SendConnector -Identity <'IdentityName'> -SmartHosts <'IP Address of Smart Host'> -DNSRoutingEnabled $false

Note: The <IdentityName> and <IP Address of Smart Host> values must be in quotes.

Repeat the procedure for each Send connector.

Check Contents

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select-Object -Property Name, Identity, SmartHosts

Identify the internet-facing connectors.

For each Send connector, if the value of "SmartHosts" does not return the Smart Host IP address, this is a finding.

Vulnerability Number

V-259670

Documentable

False

Rule Version

EX19-MB-000106

Severity Override Guidance

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select-Object -Property Name, Identity, SmartHosts

Identify the internet-facing connectors.

For each Send connector, if the value of "SmartHosts" does not return the Smart Host IP address, this is a finding.

Check Content Reference

M

Target Key

5580