When you send an e-mail message from a shared mailbox in Outlook 2007, the sent message is not saved in the Sent Items folder of the shared mailbox
KB Article: https://support.microsoft.com/kb/972148
Consider the following scenario:
You configure the DelegateSentItemsStyle registry entry for
Microsoft Office Outlook 2007.To do this, you set the DWORD value of the following registry key to 1:
HKEY_CURRENT_USERSoftwareMicrosoftOffice12.0OutlookPreferencesDelegateSentItemsStyle
- You open a shared mailbox as an additional mailbox in Outlook
2007.
In this scenario, when you send an e-mail message from the shared mailbox, the message is sent successfully. However, the sent message is not saved in the Sent Items folder of the shared mailbox.