Record Insert only if field entry doesn't already exist

Getting closer to the finish line I think. So you've identified that my problem is with my recordset filter.

$colname_getEmails = "-1";
if (isset($_POST['emailaddress'])) {
$colname_getEmails = (get_magic_quotes_gpc()) ? $_POST['emailaddress'] : addslashes($_POST['emailaddress']);
}
mysql_select_db($database_SQL_TABLE, $SQL_TABLE);
$query_getEmails = sprintf("SELECT emailaddress FROM mailmerge WHERE emailaddress = %s", GetSQLValueString($colname_getEmails, "text"));
setQueryBuilderSource($query_getEmails,$WADbSearch1,false);
$getEmails = mysql_query($query_getEmails, $SQL_TABLE) or die(mysql_error());
$row_getEmails = mysql_fetch_assoc($getEmails);
$totalRows_getEmails = mysql_num_rows($getEmails);