For over a decade, you have been able to use the address book in Outlook to lookup a person’s mail stop or find all the people in a particular mail stop.  As a person’s mailbox gets moved to the Office 365, this ability will disappear from Outlook.  Fortunately, the online staff directory will still display the mail stop information.


Old Find dialog box



Old Outlook Find dialog box with Mail Stop information

New Find dialog box

New Outlook Find dialog box without Mail Stop information