Conversations involving multiple participants, allowing collaboration and information sharing in Teams
Deleted Teams chat or group chat messages cannot be restored by end users or admins once they are deleted in the client. There is no recycle bin or restore option for regular Teams chat messages.
If messages were deleted as part of a compliance/eDiscovery purge, the user copy is removed immediately and is not recoverable for the user. A compliance copy may exist temporarily in the background (for retention/eDiscovery purposes), but it is not something that can be restored back into Teams for normal use.
If the important information was stored in shared files rather than in the text of the messages, those files might still be recoverable from SharePoint/OneDrive recycle bins, depending on where they were stored and how they were deleted.
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