I recently tried importing Outlook contacts to Em Client and the Em-recommended method is to export Outlook contacts to CSV, then import the CSV to Em. This failed to import them all several times.
Better work-around: If you import the Outlook CSV to Gmail’s Contacts, and connect Em to your Gmail account via MAPI, the contacts sync to the client (you could disconnect it at that point if you wanted) with much better results – Categories work better, contacts aren’t skipped or imported with missing data, etc.