7-bit US ASCII test is a thing of the past. 8-bit character sets (eg: the Latin-1 ISO-8859-1) have been normal for a long time. However, there is more than one 8-bit character set. To avoid character clashes, characters greater than #127 can (and should) be represented by entity references.
Languages which don't fit the 8-bit character set at all can be represented by entity or numeric references. Everything below would be legible when viewed as an unaltered web page. However, web-to-email software has to do a lot of reformatting, and much of it is based on US-ASCII, so we cannot expect too much.
Computers: Internet: Web Design and Development
Negocios: Informática: Internet: Diseño de páginas
Negocios: Informática: Internet: Diseño de páginas
Bilgisayar: İnternet: Web Tasarımı ve Geliştirme
Počítače: Internet: Tvorba a vývoj stránek
حاسوب: إنترنت: مزوِّدو خدمات إنترنت
Компьютеры: Интернет: Дизайн и разработка сайтов
Υπολογιστές: Ιντερνετ: Σχεδίαση και Φιλοξενία Ιστοσελίδων
מחשבים: אינטרנט: עיצוב ובניית אתרים