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Please kindly understand that the Outlook Management tag here we mainly focus on general issues about Outlook desktop client. Since we know very little about Active Directory, the following is for informational purposes only.
As far as I know, you can disable Microsoft Outlook signatures by creating a Configuration Policy in Microsoft Endpoint Manager (Intune) or using Group Policy.
This will make all the Outlook e-mail signature settings unavailable to users. They will not be able to add, delete, edit signatures or change the default signature settings.
In some versions of Outlook, the Signature button is also removed from the ribbon bar in the new message window.
For more specific descriptions and steps, please refer to:
https://support.exclaimer.com/hc/en-gb/articles/6811332831133.
Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
Hope this helps!
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