Verify Email Existences Via Port 25

ArrayEmailVerifier.php

<?php
namespace ArrayIterator\Email;

/**
 * Class ArrayEmailVerifier
 * @package ArrayIterator\Email
 */
class ArrayEmailVerifier
{
    protected $debugCLI = false;
    protected $error;

    const TYPE_COMMAND = 'COMMAND';
    const TYPE_RESPONSE = 'RESPONSE';
    const ERROR_CONNECT = 60;
    const ERROR_UKNOWN  = 30;
    const EMAIL_EXIST   = 250;
    const EMAIL_INVALID = 550;

    /**
     * ArrayEmailVerify constructor.
     * @param bool $debugCLI
     */
    public function __construct(bool $debugCLI = true)
    {
        $this->debugCLI = $debugCLI;
    }

    /**
     * @param string $data
     * @param string $type
     */
    protected function debug(string $data, string $type)
    {
        if (!$this->debugCLI) {
            return;
        }
        $ex = explode('.', (string) microtime(true));
        $ex = isset($ex[1]) ? $ex[1] : '0';
        while (strlen($ex) < 6) {
            $ex .= '0';
        }
        $date = gmdate('Y-m-d H:i:s.').$ex;
        $data = trim(str_replace(["\r"], '', $data));

        printf(
            "[%s][%s] %s\n",
            $date,
            strtoupper($type),
            trim($data)
        );
    }

    /**
     * @param resource $stream
     * @return array
     */
    protected function getLine($stream) : array
    {
        $data = '';
        $timeout = 5;
        $limit = 10;
        stream_set_timeout($stream, $timeout);
        $endTime = time() + $limit;
        $selR = [$stream];
        $selW = null;
        $break = false;
        while (is_resource($stream) && !feof($stream)) {
            //Must pass vars in here as params are by reference
            if (!stream_select($selR, $selW, $selW, $limit)) {
                break;
            }
            //Deliberate noise suppression - errors are handled afterwards
            $str = @fgets($stream, 512);
            $data .= $str;
            // If response is only 3 chars (not valid, but RFC5321 S4.2 says it must be handled),
            // or 4th character is a space or a line break char, we are done reading, break the loop.
            // String array access is a significant micro-optimisation over strlen
            if (!isset($str[3]) || $str[3] === ' ' || $str[3] === "\r" || $str[3] === "\n") {
                break;
            }
            // Timed-out? Log and break
            $info = stream_get_meta_data($stream);
            if ($info['timed_out']) {
                break;
            }
            // Now check if reads took too long
            if ($endTime && time() > $endTime) {
                break;
            }
        }
        if (preg_match('/^([\d]{3})[ -](?:([\d]\\.[\d]\\.[\d]{1,2}) )?/', $data, $matches)) {
            $code = (int) $matches[1];
            $code_ex = (count($matches) > 2 ? $matches[2] : null);
            // Cut off error code from each response line
            $detail = preg_replace(
                "/{$code}[ -]" .
                ($code_ex ? str_replace('.', '\\.', $code_ex) . ' ' : '') . '/m',
                '',
                $data
            );
        } else {
            // Fall back to simple parsing if regex fails
            $code = (int) substr($data, 0, 3);
            $code_ex = null;
            $detail = substr($data, 4);
        }
        return [
            'code' => $code,
            'code_ex' => $code_ex,
            'data' => $data,
        ];
    }

    /**
     * @return mixed
     */
    public function getError()
    {
        return $this->error;
    }

    private function sendCommand($stream, $command, array &$history)
    {
        $this->debug(
            sprintf('SENDING %s', $command),
            self::TYPE_COMMAND
        );
        $command = rtrim($command);
        fwrite($stream, "{$command}\r\n");
        $line = $this->getLine($stream);
        $count = 3;
        while ($count-- > 0 && ! $line['data']) {
            $line = $this->getLine($stream);
        }
        $this->debug(
            $line['data'],
            self::TYPE_RESPONSE
        );
        $history[] = $line['data'];

        return $line;
    }

    public function verify(string $email, string $host)
    {
        $response = [
            'status' => self::ERROR_UKNOWN,
            'exist' => null,
            'email' => $email,
            'host' => $host,
            'reply' => [],
            'history' => []
        ];

        $line =& $response['reply'];
        $history =& $response['history'];
        $smtpHost = "{$host}:25";
        $this->debug(
            sprintf('CONNECTING %s', $smtpHost),
            'CONNECTING'
        );

        $stream = @stream_socket_client($smtpHost, $errno, $errMsg, 5, STREAM_CLIENT_CONNECT);
        if (!$stream) {
            $this->error = $errMsg;
            $this->debug(
                sprintf('CONNECTING FAILED : %s', $errMsg),
                self::TYPE_RESPONSE
            );
            return self::ERROR_CONNECT;
        }

        $line = $this->getLine($stream);
        $count = 3;
        while ($count-- > 0 && ! $line['data']) {
            $line = $this->getLine($stream);
        }
        if (!$line['data']) {
            $this->debug(
                sprintf('COULD NOT GET RESPONSE FROM SERVER : %s', $smtpHost),
                self::TYPE_RESPONSE
            );
            $response['status'] = self::ERROR_UKNOWN;
            return $response;
        }

        $history[] = $line['data'];
        $this->debug($line['data'], self::TYPE_RESPONSE);
        $line = $this->sendCommand($stream, "EHLO $host", $history);
        $history[] = $line['data'];
        if ($line['code'] !== 250) {
            $response['status'] = $line['code'];
            $this->sendCommand($stream, "HELO $host", $history);
        }

        if ($line['code'] !== 250) {
            $response['status'] = $line['code'];
            $this->sendCommand($stream, "QUIT", $history);
            return $response;
        }

        $line = $this->sendCommand($stream, "MAIL FROM: <$email>", $history);

        if ($line['code'] !== 250) {
            $response['status'] = $line['code'];
            $this->sendCommand($stream, "QUIT", $history);
            return $response;
        }

        $line = $this->sendCommand($stream, "RCPT TO: <$email>", $history);
        $code = $line['code'];
        if ($code === 500 && $line['code_ex'] && preg_match('~Reject|Spam|5\.7~i', $line['code_ex'])) {
            $code = 450;
        }

        $response['exist'] = in_array($code, [250, 251, 450, 451, 452, 541]);
        $response['status'] = $code;
        $this->sendCommand($stream, "QUIT", $history);
        return $response;
    }
}

cli.php

<?php
/**
 * usage: php cli.php [email protected]
 */

use ArrayIterator\Email\ArrayEmailVerifier;

if (PHP_SAPI !== 'cli') {
    printf('Application only run on CLI Mode, currently %s', PHP_SAPI);
    exit();
}

$array = new ArrayEmailVerifier(true);
$email = $argv[1]??null;
if (!$email) {
    exit("PLEASE ENTER EMAIL ADDRESS\n");
}
$oldEmail = $email;
$email = filter_var($email, FILTER_VALIDATE_EMAIL);
if (!$email) {
    exit(sprintf("EMAIL %s is not valid\n", $oldEmail));
}
$domain = explode('@', $email)[1]?? null;
if (!$domain || !preg_match('~\.[^.]+$~', $domain)) {
    exit(sprintf("Domain for email %s is not valid\n", $email));
}

$limit = (int) ini_get('max_execution_time');
set_time_limit(5);
@getmxrr($domain, $mx, $weight);
set_time_limit($limit);
if (empty($mx)) {
    printf("Could not get mx for email %s\n", $email);
    exit();
}

$mx = array_combine($mx, $weight);
asort($mx);
$line = null;
foreach ($mx as $host => $weight) {
    $data = $array->verify($email, $host);
    if ($data) {
        $line = $data;
        break;
    }
}
if (!$line) {
    printf('Could not get data from email %s', $oldEmail);
    exit;
}

print_r($line);