My sent emails change language when they get to their destination. Why and how do I fix it?

my yahoo emails are changing language after i send them. The recipient receives something in Greek or in symbol form. What is going on and how do i correct it?My sent emails change language when they get to their destination. Why and how do I fix it?
It is not your fault. The person who receives the e-mail must have changed the encoding. He (or she) must press ';more';, then ';Set Encoding';, and set the encoding according to his location. I live in Greece, so I have to set my encoding to ';Greek (Windows)';.