If you are going to be sending emails to Japan you need to use iso-2022-jp encoding for the body and subject. This does not mean you have to store information in this format as the encoding can be done before the email is sent in code.
Here is a quick example of how this can be done.
582 var japeneseEncoding = Encoding.GetEncoding(LanguageEncodingConstants.JapaneseEncoding);
583
584 // Encode Body
585 message.Body = LanguageEncodeString(message.Body, japeneseEncoding);
586 message.BodyEncoding = japeneseEncoding;
587
588 // Encode subject
589 message.Subject = LanguageEncodeString(message.Subject, japeneseEncoding);
590 message.SubjectEncoding = japeneseEncoding;
Note in the above that the body and subject encoding on the message is also set.
And the method that does the encoding.
597 private static string LanguageEncodeString(string stringToEncode, Encoding newEncoding)
598 {
599 var stringBytes = Encoding.UTF8.GetBytes(stringToEncode);
600 var translatedBytes = Encoding.Convert(Encoding.UTF8, newEncoding, stringBytes);
601
602 var translatedString = newEncoding.GetString(translatedBytes);
603
604 return translatedString;
605 }