Character encoding issue

I'm using the below give code to send mail in Trukish language.

MimeMessage msg = new MimeMessage(session);

msg.setText(message, "utf-8", "html");

msg.setFrom(new InternetAddress(from));

Transport.send(msg);

But my customer says that he gets sometime unreadable characters in mail. I'm not able to understand how to solve this character encoding issue.

Should i ask him to change his mail client's character encoding settings?

If yes which one he should set.

[510 byte] By [RajeevSahu_Sahua] at [2007-11-27 10:02:57]