When working with BES 2010 Express I ran into an issue where the test utility for Exchange 2010 connection would fail on the "No Send as Permission for account operator" regardless of any changes I made to Exchange or the environment.

Turns out, this error is a false positive and can sometimes be impossible to get rid of. Here are the things you need to check, and if all is working well (testing the blackberry) then you are free to move on.
<ol>
	<li> Open Active Directory Users &amp; Computers</li>
	<li>Enable Advanced Features in AD (View, Advanced Features)</li>
	<li>Double-click (open) your BESAdmin user</li>
	<li>Security tab</li>
	<li>Add the BESAdmin user to the Security tab giving Send As, Receive As – this is in addition to the defaults that were in there.</li>
</ol>
You can also perform this step for individual users to verify the Send As right has been properly assigned.