Is it possible to decide manually when to receive email on the BB? In other words, I don't want to see the emails that my desktop computer has already downloaded. My desktop Outlook removes it from the server, but the BB often forwards emails before Outlook gets a chance to delete from server.

If your using Desktop Redirector, YES. Open Desktop Manager > Redirector Settings > Check Disable message redirection while your device is connected. If your not using Desktop Redirector, NO.