Does EOP for in house accounts require Active Directory Sync?

Question

Is it just me, or is the documentation on Office 365 filled with contradictions and not written in a way that's understandable, even for seasoned IT pros?
In short, does EOP require Active Directory to use non cloud accounts?
I'm having a problem with spam on a NON Active Directory integrated mail server.  Nowhere in any online documentation that I found (about 10 hours of googling) says that AD is required to implement EOP.
 To the contrary:
See here: http://technet.microsoft.com/en-us/library/jj871669(v=exchg.150).aspx
Q. Does the service work with legacy Exchange versions (such as Exchange Server 2010) and non-Exchange environments?
A. Yes, the service is server agnostic and can be used with any SMTP mail transfer agent.
But when I attempt to use EOP with my office 365 accounts, with local email (not exchange online), my mail is bounced because the accounts aren't found.  If I create exchange accounts, mail doesn't come to my local server, it stays at exchange online.
Am I missing something?

Answer 1

Hi,
changing the domain type to Relay disables the edge blocking feature where e-mails to invalid users are blocked by EOP. In my eyes this is a very important feature so you should use one of the following ways to have the valid recipients in EOP:
http://technet.microsoft.com/en-us/library/dn636911(v=exchg.150).aspx
Greetings
Christian
Christian Groebner MVP Forefront