InformationAll installed trusted COM addins can be trusted. Exchange Settings for the addins still override if present and this option is selected. The recommended state for this setting is: Enabled:Trust all loaded and installed COM addins.
Under normal circumstances the installed COM add-ins are applications that have been approved and intentionally deployed by the organization and therefore they should not pose a security threat. However, if malware has infected systems its possible that the malware will use the COM add-in feature to perform unauthorized actions.
SolutionTo implement the recommended configuration state, set the following Group Policy setting to Enabled.
User Configuration\Administrative Templates\Microsoft Outlook 2013\Security\Configure Add-In Trust Level
Then set the Configure Add-In Trust Level option to Trust all loaded and installed COM addins.
This setting enforces the default configuration, and therefore is unlikely to cause significant usability issues for most users.