Step #

Task

Screenshot

1

Click Modify.

2

Uncheck Microsoft Outlook.

Then, click OK.

3

Now that we've done that, close Outlook and any email windows you have open.

Open Control Panel and ensure in the View By drop down list at the top of the window is set for Small Icons to display the full contents of the Control Panel.

Click on the Mail (32-bit) link to open the Mail Setup of Outlook. 

Click Open File location.

4

Right-click and select Properties for the OST file of your email account.

5

Click Advanced.

6

Ensure that the "Allow this file to have contents indexed in addition to file properties" is checked.

7

Click OK through all the windows to apply the changes. Now we're going to re-enable the indexing function in Outlook so these changes will be picked up.

Open Outlook and then go to to File > Options > Search and the click Indexing Options. 

Click Modify.

8

Ensure that the "Microsoft Outlook" option is checked.

You've now completed the rectification process. Now try and search the shared mailbox and all should be good. It may be a bit slow to search initially, due to the indexing that is being carried out in the background. Depending on how large your email file is, it could take a few hours to complete the indexing task. Once the indexing is complete the speed of your search should improve dramatically.