You can use different mail addresses for business and leisure. You can add several mailboxes to your phone and use the same mail account both on your phone and on your PC, be it Outlook, Office 365, or any other mail account. Your mail and calendar remain in sync, and you can join meetings directly from calendar invitations. You can make use of the integrated mail and calendar so that, for example, when you have a meeting coming up, you can view the attendee list and, with a tap, access any mail or text message discussions you have had with an attendee.
For more info on creating mailboxes, see the Add a mailbox section in this user guide.
For more info on Office 365, see the video at http://www.youtube.com/watch?v=2QxiYmAerpw (in English only).