shared mailbox sent items outlook 2013

[Update]: This won't work unless you have admin rights on the computer in question (the required registry keys will not be visible), in which case speak to your IT administrator.

The resolution is as follows:

• Open the registry (careful!) by clicking Start > Run > type in 'regedit' [enter]

• Drill down to HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\Preferences

• Add a DWord called 'DelegateSentItemsStyle'. Give it a value of 1. Restart Outlook.