Outlook's new search location
Microsoft is rolling out a new Search box for Windows desktop Outlook, locating the search box at the top of the window - my change occurred just this morning!
This merges the look, feel and functionality of the desktop and online versions of Outlook and the new search engine is faster.
There are a number of other changes and you can learn more about these (and their pros and cons) by watching an excellent video by Michael Linenberger (see link below).
Most importantly, if you want to keep the search box in the same place where you have grown familiar with it, simply go to the top right corner of any screen in Outlook and turn off the ‘Coming Soon’ option. You may have to restart Outlook for this change to take effect.
Video on Outlook’s new search location by Michael Linenberger