To move an email to the "Sent Items" of the delegated mailbox it was sent from add the following registry entry.
- Click Start, click Run, type regedit, and then click OK.
- Locate and then click the following registry subkey:
HKEY_CURRENT_USER\Software\Microsoft\Office\x.0\Outlook\Preferences
Note The x.0 placeholder represents your version of Office (16.0 = Office 2016, 15.0 = Office 2013, 14.0 = Office 2010).
- On the Edit menu, point to New, and then click DWORD Value.
- Type DelegateSentItemsStyle, and then press Enter.
- Right-click DelegateSentItemsStyle, and then click Modify.
- In the Value data box, type 1, and then click OK.
- Exit Registry Editor.