Thanks, Bruce. I'll follow up today and try to see can get done.
If you want an mbox import, you need to be on Premium Yearly. If you haven't read it already, see /g/GroupManagersForum/wiki/Moving-to-Groups.io#Upload-Services for info.
I did read that, but some of the details I need were missing there, and there's nothing at all on the official documentation past. It seemed the way to get it going was to "email support", so I'll do that a second time.
Fingers crossed!
Mike
