The Delete Subscriber on Unassign of Subscriber from User or Delete User check box is clear while associating a mailbox with a user.
Procedure
On the System Manager web console, click Users > User Management > Manage Users.
On the Manage Users page, select a user and click Edit.
On the User Profile | Edit | <User Name> page, click the Communication Profile tab.
In the Messaging Profile tab, clear the check box next to the Messaging Profile label.
Click Commit.
Result
The system removes the association between the subscriber mailbox and the user. The subscriber mailbox is still provisioned on the communication management device.