We are having a bit of an argument here.
When would you give AD a .local domain and when a top level domain ?
Obviously .local isn't routeable .. but in that particular case it doesn't have to.
Basically there is one Server which supposed to run Exchange (also acting as domain controller) and one webserver which will be joined to the domain.
The exchange server will host one domain which ie. example.com .. and the webserver will host the website example.com
Now - would you name the actuall AD example.com or example.local ?