Manage Other Mailbox from OWA 2013

Hello,

We can manage other user from OWA (option/mail/option/what to manage) Exchange 2010. We upgraded our system to Exchange 2013 but we can not manage other user from OWA 2013. Is there any additonal settings to manage other mailbox from OWA 2013?

Thanks.

Murat ER Microsoft Certified Systems Administrator