Using Classic Outlook on Windows for personal email, calendar, and contact management
This and other suggestions didn't work for me.
I just wanted a way to quickly find my reply e-mail to the original one. What I finally found was this:
Under the contact address in the original e-mail, there is a blue circle with an 'i' in it, saying: "You replied to this message on (date, time)". Click at this, and a small pop-up message appears "Find related messages", click at this and it shows both the original and replied e-mail in the 'Result' column on the left.
Hope that helps.