What's Wrong With My Query To Filter Double Entries And Skip Empty Rows?

I am trying to get filter a database table.
- skip empty rows (i.e. ecardNameSender is empty)
- filter double entries

$sql = "SELECT COUNT(*) as total FROM tblEcards WHERE ecardNameSender != '' GROUP BY ecardEmailFriend";
$result = @mysql_query($sql, $connDB);
$row = mysql_fetch_assoc($result);
$totalPics = $row['total'];
echo $totalPics;
What's wrong with my query?