- Log On to Microsoft Office 365 Admin Console
- Open Microsoft Purview Admin Console
- Click Data Lifecycle Management on the left
- Click Exchange Legacy
- Click MRM Retention Tags on the left
- Click New Tag
- Give the Tag a name e.g. MHS 10 Year Hard Delete
- Click Next
- Click Automatically to entire mailbox (default)
- Click Next
- Under Retention Period – Type the amount of days to keep emails for before they automatically delete e.g. 3650
- Select Permanently delete
- Click Next – Click Submit
- Click MRM Retention Policies on the left
- Click New Policy
- Give the Policy a new name e.g. MHS – 10 Year Hard Delete
- Click Add Tag – select the newly created tag e.g. MHS – 10 Year Hard Delete
- Click Add – Click Next – Click Submit – Click Done
The Retention Policy has been created