Originally Posted by WNO
I don't have any insight into the hocus-pocus behind this, but I can confirm that the e-mails sent from your BB through the redirector, and not through the BWC, will show up in your Exchange/Outlook sent mail folder. Mail sent from Outlook will not, however, be redirected to your BB, at least in a non-BES setup. The redirector, which must always be on, processes both incoming and outgoing (that is, from BB to other addressees) mail, which I suppose it what allows it to coordinate with Exchange/Outlook.
From what I've seen, everything is via smtp. So basically the redirector software receives your responses via your exchange account, unencrypts them, and sends them out and places them in the sent folder. That's how email addresses that may only be available from inside your company will be accessible provided the redirector is running on a PC on the company network. It is pretty nice how they did it, I guess.