The applicant shall thereafter serve a notice upon each person named in the application as an expected adverse party, together with a copy of the application, stating that the application will come on for hearing at a time and place named therein. The notice shall be served as provided for the service of original notices other than by publication at least 20 days before the date of hearing. If service cannot with due diligence be so made upon any expected adverse party named in the application, the court may make such order as is just for service by publication or otherwise, or may, upon a showing of extraordinary circumstances, prescribe a hearing upon less than 20 days’ notice.