Brian Tillman wrote:

Click ViewArrange By and uncheck Show in Groups. Then click on the
Subject field to sort by the subject. Then click ViewArrange By and
check Show in Groups again.

Well, after some experimenting, I find this doesn't work as I expected.
Instead, click ViewArrange ByCurrent ViewCustomize Current ViewReset
Current ViewOK to get it back to what it should be. Then click Sort and
change the "Sort items by" drop-down to "Subject". Click OK, then OK. This
should give you what you want.
--
Brian Tillman [MVP-Outlook]