Information
This policy setting controls whether Outlook users can publish e-mail certificates to the Global Address List (GAL). The GAL contains information for all email users, distribution groups, and Exchange resources.
The recommended state for this setting is: Enabled
Only Administrators should be able to perform tasks such as publishing digital certificates to the GAL.
Solution
To establish the recommended state via configuration profiles, set the following Settings Catalog path to Enabled :
Microsoft Outlook 2016\Security\Cryptography\Do not display 'Publish to GAL' button
Impact:
Only Administrators will be able to publish a new or updated certificate to the GAL.