Okay, I posted about this some months ago and the company just got around to running it this past weekend... except it didn't do anything.
It had been set to "Generate Report Only" every Saturday night and midnight, which it had been doing reliably for months.
I switch it to "Delete Immediately" and then this past Saturday it does nothing. Wtf?
I am pretty certain I did rightclick > Apply this policy now ... I checked the scheduling, it still says Sat and midnight ... it just didn't run.
I switched it back to "Generate report only" and ran it manually it and it generated a report saying "46,000 emails and 4 GB would be deleted" - so it sees it and it works... just not when you tell it to delete.
Oh, btw, this policy is to delete any emails/items over 180 days old.