Well this is how you can set up a greek phplist installation to send greek newsletters:

First of all open texts/greek.inc and change the $strCharSet  to  ‘utf-8′;
Then save the file as UTF-8 nobom
Open admin/send_core.php and find the lines
line 1034 change .htmlentities(iconv(’ISO-8859-1′,’UTF-8′,$subject),ENT_QUOTES,’UTF-8′) to .htmlentities($subject,ENT_QUOTES,’UTF-8′)
Line 1040 change htmlentities(iconv(’ISO-8859-1′,’UTF-8′,$from),ENT_QUOTES,’UTF-8′) to htmlentities($from,ENT_QUOTES,’UTF-8′)

That’s it all done your emails will be saved [...]