We've started deleting mail over 90 days from Inbox, Deleted Items, and Sent Items. I have the policy set to apply to all 'Users with Exchange Mailbox' and when I do a 'Find Now' it returns ~1200 mailboxes. I have also set this policy to delete based on 'Received Date' using a MS KB article covering the 'how to'. So what we're seeing from the daily email that runs, is fewer and fewer mailboxes being processed:
I can't find a rhyme or reason as to why it would do this. I thought initially it was only the mailboxes that met the 90 Day threshold, but there are lots of mailboxes in the report with no mail to be deleted. It's odd that it would progressively go down. Anyone know why this happens? Is it normal?