Save Deleted Items in owner’s mailbox

I’m using an Exchange account and have also the mailbox of my boss configured in my Outlook. All works fine except that when I delete messages from this mailbox, the items are moved to my Deleted Items folder instead of the mailbox of my boss.

How can I configure this?

You can do this via the Registry (create the key if needed);

Key: HKEY_CURRENT_USER\Software\Microsoft\Office\<version>\Outlook\Options\General
Value name: DelegateWastebasketStyle
Value Type: REG_DWORD
Value: 4

When the key is set to 8 or when the key is absent, the messages you delete from secondary mailboxes will end up in the Deleted Items folder of the primary mailbox. With the value set to 4, the messages will end up in the Deleted Items folder of the mailbox you deleted it from.

Note: The value name of the key is case sensitive.