PHPmailer and Greek encoding

[johnie]

Hi. I'm sending some HTML emails through phpmailer in Greek.
However some clients can read the Greek text and others can't.

I tried to set the encoding in the class to

$mail->CharSet = "iso-8859-7";

with no luck.

Does anyone know how to deal with it?
Someone had this problem with another language?

Thanks a lot,
John