External file sharing via Whatsapp or Telegram

[ViktorMalum]

if i share a file that has a sensitivity label or configured keywords via Whatsapp or Telegram, is that considered as an external user? Can DLP policy pick up on that?
If not, is there a way to set a DLP policy to block or monitor file sharing via Whatsapp or Telegram?

[#2]

You should use Intune protection policies https://learn.microsoft.com/en-us/mem/intune/apps/app-protection-policy

If you want to control who can download a file/capture screenshot/etc you need some level of mobile device management like Intune so that you can either apply the protection at Device level (like blocking the whatsapp and other websites) or at Application level (so that anything copied from outlook/ or other MS apps cannot be sent to Whatsapp)

[#3]

You can utilize Microsoft Purview Endpoint DLP to either block or monitor file sharing on apps like WhatsApp or Telegram (via browser or desktop installed app). This tool can detect instances where sensitive items are being used and shared. For additional details, please refer to this link. https://learn.microsoft.com/en-us/purview/endpoint-dlp-getting-started