User unable to see some messages in a shared mailbox.

Question

Environment: Exchange 2016 CU16 in a DAG

I have a benefits/payroll user with access to multiple shared mailboxes. Today she mentioned that in one of them it shows there are 10 items with 3 unread messages in the Inbox folder, however when she goes to the Inbox there are only the 7 read items. She can't see the unread items. Logging into OWA and opening that shared mailbox shows the 3 unread items (all from the same sender, received last week).

• The user is not using cached Exchange mode.
• There are no rules in her mailbox or the shared mailbox.
• I've reset the View.
• I've checked to see if there were any filters applied in the View settings, and there were none.
• I've opened Outlook in safe mode.
• On a whim, I created a test user and added them to the mailbox as well. That account also can't see these three unread messages.
• I set up a profile to actually log in as the shared mailbox user and the emails show up, but they don't show up when opened as a shared mailbox.

Any ideas?

Answer 1

Can confirm the issue was with emails that were marked as Private by the sender. I added the users who access this mailbox via the standard Delegates dialog and checked the box so they can view private items, and the emails showed up for them.