I've been using Office for Mac 2011 Home & Student for quite a while.  I have several clients who provide an email address for me and previously I've imported them all into Mail on my Mac.  Although I have more than one client who utilizes Microsoft Exchange for their email, lately, I'm having problems with consistently receiving mail from one client.  So, I decided to buy the "Home & Business" version in order to utilize Outlook…hoping that will solve the problem (I know Microsoft Exchange doesn't support mobile also, so I figured…why not…)