Hi @Irin Sultana ,
Thanks for reaching out.
If you have the Azure Information Protection (AIP) client installed on their windows computers, built-in labels are the automatically added as default for the latest Windows Office apps that support labeling.
To use sensitivity labels that are built into Office desktop apps for Windows and Mac, you must use a subscription edition of Office. This labeling client doesn't support standalone editions of Office.
You would only require Microsoft 365 E5 to use the Azure Information Protection (AIP) add-in for built-in labeling in Office apps.
Reference links: https://learn.microsoft.com/en-us/purview/sensitivity-labels-versions#sensitivity-label-capabilities-in-outlook
https://learn.microsoft.com/en-us/purview/sensitivity-labels-aip
Hope this will help.
Thanks,
Shweta
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