How to disable grouping in Outlook 2010

         All messages are automatically grouped by Today, Yesterday, Monday, Tuesday, Last Week, 2 Weeks Ago, Last Month, etc…

     How can you set Outlook to show all my mail as a plain list without this grouping?

This view setting can be changed in the following way;

      * click on the "tab View" option, Then expand the Arrangement box via the Expand Ribbon Gallery button
      * Now you can disable: Show in Groups

Disable it via View Settings dialog

An alternative way to disable this option is via the View Settings dialog

     * Click on "Tab" View then select the button View Settings
     * Now select the option "Other Settings" and then disable the option: Show items in Groups

These steps can be followed on Outlook 2010 installed in Windows XP and Windows 7.