What did the court decide in Mullane v. Central Hanover Bank & Trust Co.?
Answered for: US
An elementary and fundamental requirement of due process in any proceeding which is to be accorded finality is notice reasonably calculated, under all the circumstances, to apprise interested parties of the pendency of the action and afford them an opportunity to present their objections.
The Court set the constitutional standard for adequate notice of a legal proceeding. The sentence above is the court in its own words.
This answer is true in US and nowhere else on this site. Another jurisdiction is another answer, or an honest gap: see what has been read for US.