Can't recieve e-mails

I'm currently evaluating Office365 for my company.

I've been able to move over a test domain, and add users.

The users can send out e-mails from my Office365 test user accounts without a problem, but when I try and sent to my Office365 e-mail accounts I keep getting an "Address Rejected" error.

I believe I have everything setup correctly.

Did I miss something?

Thanks

Brian