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In general, the layout button positions are as follows:
If this feature is still missing, try the following possible workarounds:
Update Outlook: Make sure your Outlook is up to date, as missing features can sometimes be due to outdated software.
Enable the Layout Tab: If the Layout tab is still missing, right-click on any column header in your inbox, select View Settings, and then choose Columns. From there, you can customize the layout.
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