Retention Policies
Configure Exchange Online retention policies to manage the lifecycle of email content. Retention policies automatically move, archive, or delete messages based on age, ensuring compliance with regulatory requirements and organizational data governance.
Note: Exchange Online uses Messaging Records Management (MRM) retention policies. For unified retention across Microsoft 365 workloads, consider Microsoft Purview retention policies.
Retention Policy List
| Column | Description |
|---|---|
| Policy Name | Display name of the retention policy |
| Retention Tags | Number of tags assigned to the policy |
| Mailboxes | Number of mailboxes using this policy |
| Default | Whether this is the default policy for new mailboxes |
Retention Tags
Retention tags define what happens to items after a specified period:
Default Policy Tags (DPT)
Applied to all items in a mailbox that don’t have a more specific tag:
- Default 2 year move to archive — Moves items older than 2 years to archive mailbox
- Default delete after 5 years — Permanently deletes items after 5 years
Retention Policy Tags (RPT)
Applied automatically to specific default folders:
| Folder | Default Action | Retention Period |
|---|---|---|
| Deleted Items | Delete | 30 days |
| Junk Email | Delete | 30 days |
| Sent Items | Move to archive | 365 days |
| Inbox | Move to archive | 2 years |
Personal Tags
Tags users can apply to individual items or folders:
- 1 Year Delete — User-applied tag to delete after 1 year
- 5 Year Delete — User-applied tag to delete after 5 years
- Never Delete — Exempt item from deletion
- 1 Year Archive — Move to archive after 1 year
Retention Actions
Move to Archive
Transfer items to the user’s archive mailbox after the retention period. Items remain searchable and accessible in the archive.
Delete and Allow Recovery
Move items to Recoverable Items folder. Items can be recovered within the deleted item retention period (default 14 days, configurable up to 30 days).
Permanently Delete
Remove items permanently after the retention period. Items cannot be recovered.
Managed Folder Assistant
The Managed Folder Assistant (MFA) is the background process that applies retention policies:
- Processes each mailbox approximately once every 7 days
- Evaluates items against assigned retention tags
- Moves, deletes, or archives items based on tag actions
- Can be manually triggered with
Start-ManagedFolderAssistantPowerShell command
Note: Changes to retention policies may take up to 7 days to take effect on all mailboxes.
Best Practices
- Use Default MRM Policy as baseline — Customize from the default rather than starting from scratch.
- Apply archive tags — Move old items to archive before deleting to preserve institutional knowledge.
- Document retention requirements — Map regulatory requirements to specific retention tags and policies.
- Test before deploying — Apply new policies to a pilot group before organization-wide rollout.
API Reference
GET /api/exchange/retention-policies
List retention policies
POST /api/exchange/retention-policies
Create retention policy
GET /api/exchange/retention-tags
List retention tags
PUT /api/exchange/retention-policies/:id/assign
Assign policy to mailboxes
POST /api/exchange/retention-policies/process
Trigger Managed Folder Assistant