Sent Items - not all showing in Entourage

I am having a problem where my expectations may not be a reality. I have
moved from Outlook to Entourage 2004 and now to 2008. I can't say that I
have noticed this in 2004, but won't rule it out. I am expecting that the
Sent items in Entourage are sync'd with the Exchange server. I use more
than 1 email client in the course of a day and/or week. It could be the
Blackberry, OWA or Outlook 2003 as well as Entourage depending on my
location and machine access at any given time. From what I can tell, the
Sent items in Entourage reflect only what was sent from Entourage and no
other client. In looking at Outlook Sent Items, it shows ALL mail moved
from any of the clients though. Also, items sent from Entourage do not
show on my Blackberry, where items sent from Outlook do.

Am I missing something? If this is not a feature of Entourage, I will be
very disappointed and may need to leave the Project Centre that I have
come to like so I can ensure that I have all of my email accessible when I
need it, from where I need it. Please tell me I don't have to go back !!