However, for some "unknown" reasons, sometimes users find mails like these will drop into their own Sent Items. That means, your work colleagues sharing the email account will not be able to keep track of these "Sent Out" emails.
To resolve the problem, try this:
- Set the DWORD value of the following registry key to 1:
Outlook 2007 HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\Preferences\DelegateSentItemsStyle
Outlook 2010 HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\Preferences\DelegateSentItemsStyle
Close your Outlook and start again. It suppose to be a known issue of Outlook 2007, but sadly carries on unresolved to Outlook 2010.