$catchError = email_send();

echo '
<div id="DivAjaxEmail">';
if($catchError == '') {
    // if `$_POST['SelectLang']` is NULL, then the language display will be the user lang.
    // The 3rd argument is `TRUE` to show a clickable Translate Id.
    echo '
    <span class="text-success font-weight-bold">'.lg('Email sent!', 'Admin', TRUE, $_POST['SelectLang']).'</span>';

} else {
    echo '
    <span class="text-danger">Error sending email</span>: '.$catchError;
}