1) CREATE A MANAGED DEFAULT FOLDER
Open EMC > Organization Configuration > Mailbox > Managed Default Folders tab > New Managed Default Folder
Name: Operations_90Days
Folder Type: Inbox
2) CONFIGURE MANAGED CONTENT SETTINGS
Right-click new default folder ‘Operations_90Days’ > New Managed Content Settings
Name: Delete Items Older Than 90Days
Message Type: All Mailbox Content
Length of retention period: 90
Retention Period Stars: When delivered, end date for calendar and recurring tasks
Action to take at the end of the rention period: Permenantly Delete
3) CREATE MANAGED FOLDER MAILBOX POLICY
In EMC > Organization Configuration > Mailbox > Managed Folder Mailbox Policies > New Managed Folder Mailbox Policy
Name: Operations_90Days_MFM
Managed folder that are associated with this policy: Operations_90Days
4) ASSIGN MANAGED FOLDER MAILBOX POLICY TO A SPECIFIC MAILBOX
In EMC > Recipient Configuration > Mailbox > open properties of the mailbox you want to apply the policy to > Mailbox Settings tab > Messaging Records Management
Check Managed folder mailbox policy
Browse and select ‘Operations_90Days_MFM’ policy you created
5) FORCE NEW POLICY TO RUN AGAINST MAILBOX
Open Administrative Exchange Management Shell prompt and run the following command:
Start-ManagedFolderAssistant -Mailbox “operations”