POP3 Collection is available with Verison 6 licenses; or request a trial license.
GateKeeper --> Email --> Collection
You can also use third party collectors; some of them have different features that could be aligned with your desired result.
With regards to WinGate collecting mail and then forwarding into the exchange mail boxes; I can't say I have configured it, but I would presume it is scenario 2 on page 45 and POP3 Collection on page 9 below; take note of the bottom of POP3 Collection section, it specifies how a loop could potentially be created when it needs to forward onto another server.
http://downloads.qbik.com/qbiknz2/downl ... ations.pdf
Does anyone else have comments on this configuration?