Hidden folder, inside Recoverable Items, where retention keeps Teams, Viva Engage and Copilot messages that were deleted or expired. eDiscovery can find them there until they're purged.
Read more: Microsoft Learn
In the Ultra Transcenders books
Each book explains SubstrateHolds in context, with comparison tables and the common traps.
Terms in this definition
- WHERE
Limits a SELECT, UPDATE or DELETE to just the rows meeting a condition. Omit it, and the statement hits every row.
- Agents (classic) API
First-generation Foundry Agent Service API, based on threads, messages and runs. It is deprecated, replaced by conversations and responses, and retires on 31 March 2027.
- eDiscovery
Locating, holding, reviewing and exporting electronic information to serve as evidence in investigations or lawsuits. Microsoft Purview covers Teams, Exchange, OneDrive, SharePoint and other sources, and E5 unlocks extra premium capabilities.
Related terms
- Recoverable Items folder
Deleted items in an Exchange Online mailbox, whether soft- or hard-deleted, move to this hidden location. If holds or retention apply, preserved copies go to subfolders named SubstrateHolds and DiscoveryHolds.