I found a way around this. The reason under “Sent mail” that Outlook is only showing the To: and cc: is for security purposes since these message shouldn’t be shared, but if you’re not sharing them and still want to see the Bcc recipients, then this is what I did…Besides the two email accounts I have with Outlook 2010, it also creates it’s own Outlook folder and in that folder there’s a sub-folder named “Sent Items”. This is where the Bcc’s will show but first it has to be activated.
To do this, two simple actions have to be done.
There are different ways of getting to them but I just go into FILE/ACCOUNTS SETTINGS/select each mail account and double click or choose ‘change’, then click and open the ‘more settings’ and then the ‘sent items’ tab and select ‘save saved items in the saved items folder on this computer’ and save the changes.
The second actions is to go to FILE/OPTIONS/MAIL/Save Messages and activate “Save copies of messages in the Sent Item folder.”
It worked for me. Hope it does for you also. I right clicked on that folder to have it "show in favorites’ with my email accounts.
Luis