EHLO Blog on Changes in Accepted Domains and Safe Senders List in Exchange 2010

I’d say good read but I wrote it and that would be  just wrong.

So instead let me just say “one more from the shameless self-promotion dept.”-

https://blogs.technet.com/b/exchange/archive/2011/07/08/accepted-domains-safe-senders-list-and-you.aspx