Outlook PC Client - Shared Mailbox - Search Not Marking as Read

Hi LosBuckeye,

The issue you are experiencing with Outlook not marking shared mailbox messages as read when you read them in search results is a known issue. Microsoft has confirmed that this is a bug and is working on a fix.

In the meantime, there are a few workarounds that you can use:

• Close and reopen the search results window. This will force Outlook to update the read status of the messages.
• Mark the messages as read manually. You can do this by right-clicking on the messages and selecting "Mark as Read."
• Use Outlook Web Access (OWA) to search for and read shared mailbox messages. OWA is not affected by this bug.

To report this issue to Microsoft, you can use the Feedback Hub in the Outlook client.

Here are a few links to reference:

• Microsoft Community thread: https://learn.microsoft.com/en-us/answers/questions/138144/question-regarding-the-read-or-unread-mark-in-outl
• Microsoft Tech Community thread: https://techcommunity.microsoft.com/t5/outlook/search-in-outlook-2016-shared-mailbox-is-not-working/m-p/133279
• Microsoft Support article: https://its.uiowa.edu/support/article/103560

The Microsoft Support article is for a slightly different issue, but it does mention that there is a known issue with shared mailboxes not marking messages as read when you read them in search results.