As many websites do not convey the language properly they try to fix that using some heuristics, but especially for small texts (like messages) that can easily fail hard leading to completely wrong pronunciation.
Mail for example tried to fix that by allowing you to annotate the language for UTF-8 embedded in mail headers and the content. Ironically while that mechanism works for display names it doesn't work for email addresses itself. And I'm not sure any mail program uses it.
As many websites do not convey the language properly they try to fix that using some heuristics, but especially for small texts (like messages) that can easily fail hard leading to completely wrong pronunciation.
Mail for example tried to fix that by allowing you to annotate the language for UTF-8 embedded in mail headers and the content. Ironically while that mechanism works for display names it doesn't work for email addresses itself. And I'm not sure any mail program uses it.