@techiD - Hey! Sorry! I didn't even see your response earlier and had given the question up for lost.
Looking at MSoft's Exchange in the cloud service, I think this is
exactly what they're looking for.
Don't know why it hadn't occurred to me since Redmond has been pushing this is the partner channel for the last year - and we're supposed to be at least suggesting it to our clients.
Unfortunately my "cloud guy" decided to hang out his own shingle a while back and that initiative was being neglected on our part.
Time to get reacquainted and caught up with that.
Thanks for the wake-up call.