Need to give Linux and Mac based users ability to grant editor access and manage delegates from their desktops

Exchange 2010 SP2. We have a large Mac and Linux based user population who need to set delegate permissions on their mailboxes. OWA does not appear to offer the option to grant rights higher then "reviewer". Outlook 2011 for Mac is not an option for our Mac users on the grounds that it does a terrible job handling large mailboxes, of which we have many.

Is there any way to enable or otherwise offer this capability to non-Windows users?

Christiaan

Christiaan Zaluzec