Problem sending Newsletter in Greek

Hi. I'm having a problem sending Newsletter in Greek. I try sending the Greek newsletter with my profile language in English and in Greek but my members receive a message in funky characters. No matter what encoding they put it doesn't fix. Can anyone tell me what to do? At the moment I'm forced to send the message I want via PM. It's OK for now that I still have less than 50 members but what happens when I get more than 50:?:

This happens because some of the characters in Greek are not supported.

I know the reason why it happens. What I need is a solution. Normally the problem is solved by changing the encoding when you read the email. This is not the case here. Thanks for the reply though.