Installing Exchange on a domain controller?

We are very small business firm like less than 10 people. I planning to setup new server. Initially I thought install AD, DNS, DHCP, DC and Exchange on same server. Microsoft not recommending all in my serverInstalling Exchange on a domain controller is not recommended.

So give me suggestion, Is it OK install everything on server for small company like us? or 

create 1 virtual and install Exchange on that server and rest will be on base?. 

ItsMeSri SP 2013 Foundation