The Add-In Trust Level must be configured.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-228436SRG-APP-000210DTOO236SV-228436r508021_rule2022-03-112

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.

✔️ 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)".