This workaround will guide you to search emails across all mailboxes by the Instant Search feature, and then copy search results into the destination folder in Outlook.

1. In the Navigation Pane, select the email account that you will create a search folder into, and click Folder > New Folder. See screenshot:

2. In the opening Create New Folder dialog box, type a name for the new folder into the Name box, and click the OK button. See screenshot:

3. Select any mail folder, type the search criteria into the Instant Search box, and then click Search > All Mailboxes (or All Mail Items). See screenshot:

4. Now all emails meeting the search criteria are found out across all mailboxes. Select all of them, and press Ctrl + C keys simultaneously to copy them.

Note: You can select all search results with clicking the first one in the mail list, and then pressing the Ctrl + Shift+ End keys simultaneously.

5. Click to open the new created folder, and press the Ctrl + V keys simultaneously to paste all search results.

Now all search results are copied to the new created folder. However, this folder is not a real search folder, and emails won't be automatically added into this folder if meeting the search criteria in future.

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