[Exchange] Best Practices/Steps for Exchange Cloud to On Premises

[N Parr]

I'm Googling around for this and all I get is office365 articles.  How to 
coexist, how to migrate to 365.  Maybe I'm not digging far enough in to the 
results.  Our goal is to migrate users from a 3rd party host currently being 
used to a new in house 2013 environment.   I know it seems counterintuitive to 
the world direction but powers that be have decided there's a significant cost 
savings considering all the other licensing we are doing and the # of users.
Thanks