Basic infrastructure preparation
To simplify our approach, let's start with a basic source Exchange 2013 environment. The following is a diagram of the scope of the requirements:

Let's focus on the necessary requirements for the following components:
- Directory Synchronization server
- Active Directory Federation services
- Exchange Hybrid server
Directory Synchronization server
Only one Directory Synchronization server can be actively used within a single Office 365 subscription. The following are the base requirements for this server:
- 64-bit deployment
- Windows Server 2008 SP1+,Windows Server 2008 R2 SP1+, Windows Server 2012, or Windows Server 2012 R2
- AD domain ...
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