我也有这个问题。我设置了正确的设置，并启用了不太安全的应用程序，但它仍然不起作用。最后，我启用了这个https://accounts.google.com/UnlockCaptcha，它为我工作了。

我也有这个问题。我设置了正确的设置，并启用了不太安全的应用程序，但它仍然不起作用。最后，我启用了这个https://accounts.google.com/UnlockCaptcha，它为我工作了。

使用Swift mailer，很容易通过Gmail凭据发送邮件:

<?php
require_once 'swift/lib/swift_required.php';

$transport = Swift_SmtpTransport::newInstance('smtp.gmail.com', 465, "ssl")
  ->setUsername('GMAIL_USERNAME')
  ->setPassword('GMAIL_PASSWORD');

$mailer = Swift_Mailer::newInstance($transport);

$message = Swift_Message::newInstance('Test Subject')
  ->setFrom(array('abc@example.com' => 'ABC'))
  ->setTo(array('xyz@test.com'))
  ->setBody('This is a test mail.');

$result = $mailer->send($message);
?>

Gmail需要端口465，它也是来自phpmailer的代码

SwiftMailer可以使用外部服务器发送电子邮件。

下面是一个演示如何使用Gmail服务器的例子:

require_once "lib/Swift.php";
require_once "lib/Swift/Connection/SMTP.php";

//Connect to localhost on port 25
$swift =& new Swift(new Swift_Connection_SMTP("localhost"));


//Connect to an IP address on a non-standard port
$swift =& new Swift(new Swift_Connection_SMTP("217.147.94.117", 419));


//Connect to Gmail (PHP5)
$swift = new Swift(new Swift_Connection_SMTP(
    "smtp.gmail.com", Swift_Connection_SMTP::PORT_SECURE, Swift_Connection_SMTP::ENC_TLS));

通过Gmail使用phpMailer库发送邮件 请从Github下载库文件

<?php
/**
 * This example shows settings to use when sending via Google's Gmail servers.
 */
//SMTP needs accurate times, and the PHP time zone MUST be set
//This should be done in your php.ini, but this is how to do it if you don't have access to that
date_default_timezone_set('Etc/UTC');
require '../PHPMailerAutoload.php';
//Create a new PHPMailer instance
$mail = new PHPMailer;
//Tell PHPMailer to use SMTP
$mail->isSMTP();
//Enable SMTP debugging
// 0 = off (for production use)
// 1 = client messages
// 2 = client and server messages
$mail->SMTPDebug = 2;
//Ask for HTML-friendly debug output
$mail->Debugoutput = 'html';
//Set the hostname of the mail server
$mail->Host = 'smtp.gmail.com';
// use
// $mail->Host = gethostbyname('smtp.gmail.com');
// if your network does not support SMTP over IPv6
//Set the SMTP port number - 587 for authenticated TLS, a.k.a. RFC4409 SMTP submission
$mail->Port = 587;
//Set the encryption system to use - ssl (deprecated) or tls
$mail->SMTPSecure = 'tls';
//Whether to use SMTP authentication
$mail->SMTPAuth = true;
//Username to use for SMTP authentication - use full email address for gmail
$mail->Username = "username@gmail.com";
//Password to use for SMTP authentication
$mail->Password = "yourpassword";
//Set who the message is to be sent from
$mail->setFrom('from@example.com', 'First Last');
//Set an alternative reply-to address
$mail->addReplyTo('replyto@example.com', 'First Last');
//Set who the message is to be sent to
$mail->addAddress('whoto@example.com', 'John Doe');
//Set the subject line
$mail->Subject = 'PHPMailer GMail SMTP test';
//Read an HTML message body from an external file, convert referenced images to embedded,
//convert HTML into a basic plain-text alternative body
$mail->msgHTML(file_get_contents('contents.html'), dirname(__FILE__));
//Replace the plain text body with one created manually
$mail->AltBody = 'This is a plain-text message body';
//Attach an image file
$mail->addAttachment('images/phpmailer_mini.png');
//send the message, check for errors
if (!$mail->send()) {
    echo "Mailer Error: " . $mail->ErrorInfo;
} else {
    echo "Message sent!";
}