I would like to receive calls from an * box that is configured to trunk all calls starting with the digit 4 to my FS box.

What happens now is that incoming calls are rejected with a 407, I set the param auth-calls to false for public DID numbers as shown below but this did not help.  

<extension name="public_did">

 <condition field="destination_number" expression="^4(\d{4})$">

  <param name="auth-calls" value="false"/>

  <action application="transfer" data="$1 XML default"/>

 </condition>

</extension>