Email with spam protection; Internet Service Providers (ISP) hosted email is not secure enough these days. An ISP is in the business to provide you internet they have networking technology and equipment; their forte is not to run an email server. Unless your email is setup with SSL; your data is readable by an internet sniffer. Email can be just like cookies and you can get targeted for spoof emails just like you get targeted for ads in your browsers. There are lots of business reasons to want a hosted exchange solution but for security it is encrypted in your connect to outlook; it is encrypted at the hosting company; and your administrator can make policies that must be abided by so that everyone has strong passwords and they are changed on a regular basis. Spam services provide several layers of protection including the ability to stop botnets.