A run down of some of the common concerns people have when installing the first Exchange 2010 server into their production environment.
How to avoid creating an infinite email routing loop in Exchange Server 2007/2010 when configuring Internal Relay domains.
Exchange Server 2010 allows you to restrict who can send to distribution groups. You can do this in different ways, but it is important to understand the pros and cons of each type of distribution group protection so that you choose the correct one for your situation.
Microsoft has released this video from MCM instructor Brian Reid about the header firewall, part of the Exchange Transport architecture that is covered in the Microsoft Certified Master program in depth.