No judgment shall be rendered upon, or by virtue of, any instrument in writing authorizing the acceptance of service of process by another on behalf of any person who is obligated upon such instrument, when such service is accepted as therein authorized, unless the person accepting service shall have made and filed with the court an affidavit showing that he mailed or caused to be mailed to the defendant at his last known post-office address at least ten days before such judgment is to be rendered a notice stating the time when and place where the entry of such judgment would be requested.