soap sample on retrieving_the_email_folder_hierarchy.htm

retrieve-email-folder-heirarchy.xml

<soap:Body>
  <RetrieveRequestMsg xmlns="http://exacttarget.com/wsdl/partnerAPI">
    <RetrieveRequest>
      <ObjectType>DataFolder</ObjectType>
      <Properties>Client.ID</Properties>
      <Properties>Name</Properties>
      <Properties>ID</Properties>
      <Properties>ObjectID</Properties>
      <Properties>ContentType</Properties>
      <!--Parent Details-->
      <Properties>ParentFolder.ContentType</Properties>
      <Properties>ParentFolder.ID</Properties>
      <Properties>ParentFolder.ObjectID</Properties>
      <Properties>ParentFolder.Name</Properties>
      <Filter xsi:type="SimpleFilterPart">
        <Property>ContentType</Property>
        <SimpleOperator>equals</SimpleOperator>
        <Value>email</Value>
      </Filter>
      <QueryAllAccounts>true</QueryAllAccounts>
    </RetrieveRequest>
  </RetrieveRequestMsg>
</soap:Body>