The Add-In Trust Level must be configured.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-228436	SRG-APP-000210	DTOO236	SV-228436r508021_rule	2022-03-11	2

Description
All installed trusted COM addins can be trusted. Exchange Settings for the addins still override if present and this option is selected.

ℹ️ Check
Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Security "Configure Add-In Trust Level" is set to "Enabled (Trust all loaded and installed COM addins)". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\16.0\outlook\security Criteria: If the value AddinTrust is REG_DWORD = 1, this is not a finding.

ℹ️ Check

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Security "Configure Add-In Trust Level" is set to "Enabled (Trust all loaded and installed COM addins)". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\16.0\outlook\security Criteria: If the value AddinTrust is REG_DWORD = 1, this is not a finding.

✔️ Fix
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Security "Configure Add-In Trust Level" to "Enabled (Trust all loaded and installed COM addins)".