I often search for e-mails that I sent or received on a certain date. For that purpose I am using the German keyword "gesendet: <date>", probably "sent: <date>" in Englisch.
In earlier versions of Outlook, this type of search appeared in a list of my recent searches, but now it is completely gone. All I have left is a list "Vorgeschlagene Suchen" (probably "Recommended Searches) which does not contain my previous entries. So the current list is more or less useless for my purpose