You may find a situation where you need to remove all of the email and content in an Exchange mailbox but retain the mailbox itself.
Below are the Exchange Management Shell commands to remove all of the contents of a mailbox:
Option 1)
Search-Mailbox -Identity “April Stewart” -DeleteContent
Option 2)
Export-Mailbox -identity “April Stewart” -DeleteContent
Your account must be a member of the group: “Mailbox Import Export”.
To find out what Exchange groups you are in:
Get-ManagementRoleAssigment -RoleAssignee “JohnDoe_Admin”
Note: Organization Management does not have the special permission that “Mailbox Import Export” has which allows deleting of the mailbox content.
Use the following Exchange Management Shell command to assign the Mailbox Import Export permissions to your administrator account:
New-ManagementRoleAssignment -Role “Mailbox Import Export” -User “JohnDoe_Admin”
Resources:
https://technet.microsoft.com/en-us/library/dd298173.aspx