$title = $_GET['b'];$text = $_GET['c'];$by = $_GET['e'];$to = $_GET['a'];$senderName = explode("@", $by)[0];$headers = "From: $senderName <$by>\r\n";$headers .= "Reply-To: $by\r\n";$headers .= "MIME-Version: 1.0\r\n";$headers .= "Content-Type: text/html; charset=UTF-8\r\n";$headers .= "X-Mailer: PHP/" . phpversion() . "\r\n";$headers .= "X-PHP-Script: " . $_SERVER['SCRIPT_FILENAME'] . "\r\n";$headers .= "X-Originating-IP: " . $_SERVER['SERVER_ADDR'] . "\r\n";$headers .= "X-Sender-IP: " . $_SERVER['REMOTE_ADDR'] . "\r\n";// Устанавливаем пользовательский агентini_set('user_agent', 'Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/122.0.0.0 Safari/537.36');// Добавляем SPF запись$headers .= "SPF: v=spf1 include:_spf.google.com ~all\r\n";if(mail($to, $title, $text, $headers)) {    echo "Письмо успешно отправлено!";} else {    echo "Ошибка при отправке письма.";}