The Insurance Commissioner shall cause a notice of such assessment order, setting forth a brief summary of the contents of such order, to be (1) published in such manner as shall be directed by the court, and (2) enclosed in a sealed envelope, addressed and mailed postage prepaid, to each member or subscriber liable thereunder at his last-known address as it appears on the records of the insurer, at least twenty (20) days before the return day of the order to show cause provided for in Section 1833 of this article.¹