Circumstances vary too widely. It is possible, however, to lay out some basic guidelines which, in combination with an understanding of the region's cultural signposts and individual countries, will serve the international business person well. Everybody is different, even in homogeneous, collectivist societies like Japan and South Korea. People within a family or an organization are different. Organizations are different from one another.
Nations are different.
However, before a relationship is established, a communicator needs to make some assumptions about the person to whom a communication is addressed. A basic assumption involves the Formality Factor. Before embarking on communications to a person or organization you do not know, assess the probable Formality Factor. That is, take a guess at what is the probable degree of formality the person or organization will expect from you.