Running your own email servers doesn’t do anything to differentiate your business from the competition (except in a bad way, if you get hacked). But avoiding the effort of managing and monitoring your own mail server isn’t the only advantage of a cloud service.
Article Link: http://www.infoworld.com/article/3177720/email/why-email-is-safer-in-office-365-than-on-your-exchange-server.html#tk.rss_all