code: def mailbox!(mbox)
        nbuild[NS_EWS_TYPES].Mailbox {
          name!(mbox[:name]) if mbox[:name]
          email_address!(mbox[:email_address]) if mbox[:email_address]
          address!(mbox[:address]) if mbox[:address] # for Availability query
          routing_type!(mbox[:routing_type]) if mbox[:routing_type]
          mailbox_type!(mbox[:mailbox_type]) if mbox[:mailbox_type]
          item_id!(mbox[:item_id]) if mbox[:item_id]
        }
      end
docs: Build the Mailbox element.
   This element is commonly used for delegation. Typically passing an
     email_address is sufficient
   @see http://msdn.microsoft.com/en-us/library/aa565036.aspx
   @param [Hash] mailbox A well-formated hash