* PHPMailer RFC821 SMTP email transport class.
* @see https://github.com/PHPMailer/PHPMailer/ The PHPMailer GitHub project
* @author Marcus Bointon (Synchro/coolbru) <phpmailer@synchromedia.co.uk>
* @author Jim Jagielski (jimjag) <jimjag@gmail.com>
* @author Andy Prevost (codeworxtech) <codeworxtech@users.sourceforge.net>
* @author Brent R. Matzelle (original founder)
* @copyright 2012 - 2020 Marcus Bointon
* @copyright 2010 - 2012 Jim Jagielski
* @copyright 2004 - 2009 Andy Prevost
* @license https://www.gnu.org/licenses/old-licenses/lgpl-2.1.html GNU Lesser General Public License
* @note This program is distributed in the hope that it will be useful - WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE.
namespace PHPMailer\PHPMailer;
* PHPMailer RFC821 SMTP email transport class.
* Implements RFC 821 SMTP commands and provides some utility methods for sending mail to an SMTP server.
* @author Marcus Bointon <phpmailer@synchromedia.co.uk>
* The PHPMailer SMTP version number.
* SMTP line break constant.
* The SMTP port to use if one is not specified.
* The SMTPs port to use if one is not specified.
const DEFAULT_SECURE_PORT = 465;
* The maximum line length allowed by RFC 5321 section 4.5.3.1.6,
* *excluding* a trailing CRLF break.
* @see https://www.rfc-editor.org/rfc/rfc5321#section-4.5.3.1.6
const MAX_LINE_LENGTH = 998;
* The maximum line length allowed for replies in RFC 5321 section 4.5.3.1.5,
* *including* a trailing CRLF line break.
* @see https://www.rfc-editor.org/rfc/rfc5321#section-4.5.3.1.5
const MAX_REPLY_LENGTH = 512;
* Debug level for no output.
* Debug level to show client -> server messages.
* Debug level to show client -> server and server -> client messages.
* Debug level to show connection status, client -> server and server -> client messages.
const DEBUG_CONNECTION = 3;
* Debug level to show all messages.
const DEBUG_LOWLEVEL = 4;
* * self::DEBUG_OFF (`0`) No debug output, default
* * self::DEBUG_CLIENT (`1`) Client commands
* * self::DEBUG_SERVER (`2`) Client commands and server responses
* * self::DEBUG_CONNECTION (`3`) As DEBUG_SERVER plus connection status
* * self::DEBUG_LOWLEVEL (`4`) Low-level data output, all messages.
public $do_debug = self::DEBUG_OFF;
* How to handle debug output.
* * `echo` Output plain-text as-is, appropriate for CLI
* * `html` Output escaped, line breaks converted to `<br>`, appropriate for browser output
* * `error_log` Output to error log as configured in php.ini
* Alternatively, you can provide a callable expecting two params: a message string and the debug level:
* $smtp->Debugoutput = function($str, $level) {echo "debug level $level; message: $str";};
* Alternatively, you can pass in an instance of a PSR-3 compatible logger, though only `debug`
* $mail->Debugoutput = new myPsr3Logger;
* @var string|callable|\Psr\Log\LoggerInterface
public $Debugoutput = 'echo';
* @see https://en.wikipedia.org/wiki/Variable_envelope_return_path
* @see https://www.postfix.org/VERP_README.html Info on VERP
* Whether to use SMTPUTF8.
* @see https://www.rfc-editor.org/rfc/rfc6531
public $do_smtputf8 = false;
* The timeout value for connection, in seconds.
* Default of 5 minutes (300sec) is from RFC2821 section 4.5.3.2.
* This needs to be quite high to function correctly with hosts using greetdelay as an anti-spam measure.
* @see https://www.rfc-editor.org/rfc/rfc2821#section-4.5.3.2
* How long to wait for commands to complete, in seconds.
* Default of 5 minutes (300sec) is from RFC2821 section 4.5.3.2.
* Patterns to extract an SMTP transaction id from reply to a DATA command.
* The first capture group in each regex will be used as the ID.
* MS ESMTP returns the message ID, which may not be correct for internal tracking.
protected $smtp_transaction_id_patterns = [
'exim' => '/[\d]{3} OK id=(.*)/',
'sendmail' => '/[\d]{3} 2\.0\.0 (.*) Message/',
'postfix' => '/[\d]{3} 2\.0\.0 Ok: queued as (.*)/',
'Microsoft_ESMTP' => '/[0-9]{3} 2\.[\d]\.0 (.*)@(?:.*) Queued mail for delivery/',
'Amazon_SES' => '/[\d]{3} Ok (.*)/',
'SendGrid' => '/[\d]{3} Ok: queued as (.*)/',
'CampaignMonitor' => '/[\d]{3} 2\.0\.0 OK:([a-zA-Z\d]{48})/',
'Haraka' => '/[\d]{3} Message Queued \((.*)\)/',
'ZoneMTA' => '/[\d]{3} Message queued as (.*)/',
'Mailjet' => '/[\d]{3} OK queued as (.*)/',
'Gsmtp' => '/[\d]{3} 2\.0\.0 OK (.*) - gsmtp/',
* Allowed SMTP XCLIENT attributes.
* Must be allowed by the SMTP server. EHLO response is not checked.
* @see https://www.postfix.org/XCLIENT_README.html
public static $xclient_allowed_attributes = [
'NAME', 'ADDR', 'PORT', 'PROTO', 'HELO', 'LOGIN', 'DESTADDR', 'DESTPORT'
* The last transaction ID issued in response to a DATA command,
protected $last_smtp_transaction_id;
* The socket for the server connection.
* Error information, if any, for the last SMTP command.
* The reply the server sent to us for HELO.
* If null, no HELO string has yet been received.
* The set of SMTP extensions sent in reply to EHLO command.
* Indexes of the array are extension names.
* Value at index 'HELO' or 'EHLO' (according to command that was sent)
* represents the server name. In case of HELO it is the only element of the array.
* Other values can be boolean TRUE or an array containing extension options.
* If null, no HELO/EHLO string has yet been received.
* The most recent reply received from the server.
protected $last_reply = '';
* Output debugging info via a user-selected method.
* @param string $str Debug string to output
* @param int $level The debug level of this message; see DEBUG_* constants
* @see SMTP::$Debugoutput
protected function edebug($str, $level = 0)
if ($level > $this->do_debug) {
//Is this a PSR-3 logger?
if ($this->Debugoutput instanceof \Psr\Log\LoggerInterface) {
//Remove trailing line breaks potentially added by calls to SMTP::client_send()
$this->Debugoutput->debug(rtrim($str, "\r\n"));
//Avoid clash with built-in function names
if (is_callable($this->Debugoutput) && !in_array($this->Debugoutput, ['error_log', 'html', 'echo'])) {
call_user_func($this->Debugoutput, $str, $level);
switch ($this->Debugoutput) {
/** @noinspection ForgottenDebugOutputInspection */
//Cleans up output a bit for a better looking, HTML-safe output
echo gmdate('Y-m-d H:i:s'), ' ', htmlentities(
preg_replace('/[\r\n]+/', '', $str),
$str = preg_replace('/\r\n|\r/m', "\n", $str);
echo gmdate('Y-m-d H:i:s'),
//Indent for readability, except for trailing break
* Connect to an SMTP server.
* @param string $host SMTP server IP or host name
* @param int $port The port number to connect to
* @param int $timeout How long to wait for the connection to open
* @param array $options An array of options for stream_context_create()
public function connect($host, $port = null, $timeout = 30, $options = [])
//Clear errors to avoid confusion
//Make sure we are __not__ connected
if ($this->connected()) {
//Already connected, generate error
$this->setError('Already connected to a server');
$port = self::DEFAULT_PORT;
//Connect to the SMTP server
"Connection: opening to $host:$port, timeout=$timeout, options=" .
(count($options) > 0 ? var_export($options, true) : 'array()'),
$this->smtp_conn = $this->getSMTPConnection($host, $port, $timeout, $options);
if ($this->smtp_conn === false) {
//Error info already set inside `getSMTPConnection()`
$this->edebug('Connection: opened', self::DEBUG_CONNECTION);
$this->last_reply = $this->get_lines();
$this->edebug('SERVER -> CLIENT: ' . $this->last_reply, self::DEBUG_SERVER);
$responseCode = (int)substr($this->last_reply, 0, 3);
if ($responseCode === 220) {
//Anything other than a 220 response means something went wrong
//RFC 5321 says the server will wait for us to send a QUIT in response to a 554 error
//https://www.rfc-editor.org/rfc/rfc5321#section-3.1
if ($responseCode === 554) {
//This will handle 421 responses which may not wait for a QUIT (e.g. if the server is being shut down)
$this->edebug('Connection: closing due to error', self::DEBUG_CONNECTION);
* Create connection to the SMTP server.
* @param string $host SMTP server IP or host name
* @param int $port The port number to connect to
* @param int $timeout How long to wait for the connection to open
* @param array $options An array of options for stream_context_create()
protected function getSMTPConnection($host, $port = null, $timeout = 30, $options = [])
//This is enabled by default since 5.0.0 but some providers disable it
//Check this once and cache the result
if (null === $streamok) {
$streamok = function_exists('stream_socket_client');
$socket_context = stream_context_create($options);
set_error_handler(function () {
call_user_func_array([$this, 'errorHandler'], func_get_args());
$connection = stream_socket_client(
//Fall back to fsockopen which should work in more places, but is missing some features
'Connection: stream_socket_client not available, falling back to fsockopen',
set_error_handler(function () {
call_user_func_array([$this, 'errorHandler'], func_get_args());
//Verify we connected properly
if (!is_resource($connection)) {
'Failed to connect to server',
'SMTP ERROR: ' . $this->error['error']
//SMTP server can take longer to respond, give longer timeout for first read
//Windows does not have support for this timeout function
if (strpos(PHP_OS, 'WIN') !== 0) {
$max = (int)ini_get('max_execution_time');
//Don't bother if unlimited, or if set_time_limit is disabled
if (0 !== $max && $timeout > $max && strpos(ini_get('disable_functions'), 'set_time_limit') === false) {
@set_time_limit($timeout);
stream_set_timeout($connection, $timeout, 0);
* Initiate a TLS (encrypted) session.
public function startTLS()
if (!$this->sendCommand('STARTTLS', 'STARTTLS', 220)) {
//Allow the best TLS version(s) we can
$crypto_method = STREAM_CRYPTO_METHOD_TLS_CLIENT;
//PHP 5.6.7 dropped inclusion of TLS 1.1 and 1.2 in STREAM_CRYPTO_METHOD_TLS_CLIENT
//so add them back in manually if we can
if (defined('STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT')) {
$crypto_method |= STREAM_CRYPTO_METHOD_TLSv1_2_CLIENT;
$crypto_method |= STREAM_CRYPTO_METHOD_TLSv1_1_CLIENT;
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
