There's mail support built into OS X Server. Will it handle as many users as an exchange server? Probably not, but the built in mail clients on all of the iOS a

There's mail support built into OS X Server. Will it handle as many users as an exchange server? Probably not, but the built in mail clients on all of the iOS and Mac devices handle exchange email _relatively_ well (duck and hide!). As for making it easy to transition off of Office, Pages, Numbers and Keynote will all open up all of the microsoft file formats.