Litigation Hold
Preserve mailbox content for legal discovery, regulatory requirements, or internal investigations. Litigation Hold prevents permanent deletion of emails, calendar items, and other mailbox content regardless of user actions.
Warning: Failure to preserve evidence can result in sanctions, adverse inference, or case dismissal. Enable Litigation Hold as soon as you reasonably anticipate litigation or receive a preservation notice.
Litigation Hold List
| Column | Description |
|---|---|
| User | Mailbox owner display name and email |
| Hold Status | Enabled or Disabled |
| Hold Duration | Time-based or Indefinite |
| Start Date | When hold was enabled |
| Note | Internal note (case reference) |
| User Notified | Whether user received hold notice |
How Litigation Hold Works
Recoverable Items Folder
When hold is enabled, items deleted by users (including those purged from Deleted Items) are moved to the Recoverable Items folder. This hidden folder preserves content for the hold duration.
- Deletions subfolder: Soft-deleted items
- Purges subfolder: Hard-deleted items
- Versions subfolder: Original versions of modified items
Copy-on-Write
When items are modified or deleted, the original version is automatically copied to the Versions subfolder before the change is applied. This preserves the exact state at time of hold.
Storage Quota
Recoverable Items has a default 30 GB quota for mailboxes on hold (increased from 100 GB to 110 GB for the entire mailbox). Auto-expanding archive can provide additional space.
Hold Duration Options
Indefinite Hold
Content preserved forever until hold is explicitly removed. Use when litigation duration is unknown.
Time-Based Hold
Preserve items for specified number of days. Items older than the duration are purged. Use for regulatory retention.
Enabling Litigation Hold
- Select Mailbox — Choose the user mailbox to place on hold. Can also hold shared mailboxes and inactive mailboxes.
- Configure Duration — Leave blank for indefinite hold, or specify days for time-based retention.
- Add Hold Note — Document the reason for hold, case number, or matter reference. This is for internal tracking only.
- User Notification (Optional) — Optionally notify user that their mailbox is on hold. URL can link to hold policy or legal notice.
Note: Hold takes effect immediately but may take up to 60 minutes to fully propagate. New items are protected immediately.
What Gets Preserved
- Email messages (sent, received, drafts)
- Calendar items and meeting requests
- Contacts
- Tasks
- Notes
- Deleted items and purged items
- Modified item versions (original preserved)
Litigation Hold vs Other Holds
| Feature | Litigation Hold | eDiscovery Hold |
|---|---|---|
| Scope | Entire mailbox | Query-based (specific content) |
| Configuration | Simple on/off | Case-based, keyword filters |
| Use Case | Preserve everything | Targeted preservation |
| License | Exchange Online Plan 2 | E3/E5 or Compliance add-on |
Releasing a Hold
Warning: Before releasing, confirm with legal that preservation is no longer required. Document the authorization to release. Consider exporting preserved content first.
After Release
Items in Recoverable Items become subject to normal retention. MRM policies will process the folder within 7 days. Previously held items may be permanently deleted.
Best Practices
- Enable hold promptly — Place hold as soon as you anticipate litigation or receive notice.
- Document everything — Record who authorized the hold, the case reference, and the scope.
- Don’t notify users unnecessarily — User notification is optional. Consult legal on whether to inform.
- Monitor storage — Long-term holds can consume significant storage. Enable auto-expanding archive.
API Reference
GET /api/exchange/litigation-hold
List mailboxes on litigation hold
POST /api/exchange/litigation-hold/:mailboxId
Enable litigation hold
DELETE /api/exchange/litigation-hold/:mailboxId
Remove litigation hold
GET /api/exchange/mailboxes/:id/hold-status
Get hold status for mailbox