Gmail需要端口465，它也是来自phpmailer的代码

I have a solution for GSuite accounts that doesnt have the "@gmail.com" sufix. Also I think it will work for GSuite accounts with the @gmail.com but havent tried it. First you should have the privileges to change the option "allos¿w less secure app" for your GSuite account. If you have the privileges (you can check in account settings->security) then you have to deactivate "two step factor authentication" go to the end of the page and set to "yes" for allow less secure applications. That's all. If you dont have privileges to change those options the solution for this thread will not work. Check https://support.google.com/a/answer/6260879?hl=en to make changes to "allow less..." option.

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);
?>

我不推荐Pear Mail。自2010年以来就没有更新过。还要读取源文件;源代码几乎过时了，是用php4风格写的，很多错误/ bug都被贴出来了(谷歌it)。我正在使用Swift Mailer。

Swift Mailer集成到任何用PHP 5编写的web应用程序中，提供了一种灵活而优雅的面向对象的方法来发送具有多种功能的电子邮件。

使用SMTP, sendmail, postfix或自定义传输发送电子邮件 实现你自己。 支持需要用户名和密码和/或加密的服务器。 在不剥离请求数据的情况下保护头部注入攻击 内容。 发送MIME兼容的HTML/多部分电子邮件。 使用事件驱动的插件来定制库。 处理内存较低的大型附件和内联/嵌入式图像 使用。

这是一个免费的开源软件，你可以下载Swift Mailer并上传到你的服务器上。(功能列表从所有者网站复制)。

Gmail SSL/SMTP和Swift Mailer的工作示例在这里…

// Swift Mailer Library
require_once '../path/to/lib/swift_required.php';

// Mail Transport
$transport = Swift_SmtpTransport::newInstance('ssl://smtp.gmail.com', 465)
    ->setUsername('username@gmail.com') // Your Gmail Username
    ->setPassword('my_secure_gmail_password'); // Your Gmail Password

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

// Create a message
$message = Swift_Message::newInstance('Wonderful Subject Here')
    ->setFrom(array('sender@example.com' => 'Sender Name')) // can be $_POST['email'] etc...
    ->setTo(array('receiver@example.com' => 'Receiver Name')) // your email / multiple supported.
    ->setBody('Here is the <strong>message</strong> itself. It can be text or <h1>HTML</h1>.', 'text/html');

// Send the message
if ($mailer->send($message)) {
    echo 'Mail sent successfully.';
} else {
    echo 'I am sure, your configuration are not correct. :(';
}

<?php
date_default_timezone_set('America/Toronto');

require_once('class.phpmailer.php');
//include("class.smtp.php"); // optional, gets called from within class.phpmailer.php if not already loaded

$mail             = new PHPMailer();

$body             = "gdssdh";
//$body             = eregi_replace("[\]",'',$body);

$mail->IsSMTP(); // telling the class to use SMTP
//$mail->Host       = "ssl://smtp.gmail.com"; // SMTP server
$mail->SMTPDebug  = 1;                     // enables SMTP debug information (for testing)
                                           // 1 = errors and messages
                                           // 2 = messages only
$mail->SMTPAuth   = true;                  // enable SMTP authentication
$mail->SMTPSecure = "ssl";                 // sets the prefix to the servier
$mail->Host       = "smtp.gmail.com";      // sets GMAIL as the SMTP server
$mail->Port       = 465;                   // set the SMTP port for the GMAIL server
$mail->Username   = "user@gmail.com";  // GMAIL username
$mail->Password   = "password";            // GMAIL password

$mail->SetFrom('contact@prsps.in', 'PRSPS');

//$mail->AddReplyTo("user2@gmail.com', 'First Last");

$mail->Subject    = "PRSPS password";

//$mail->AltBody    = "To view the message, please use an HTML compatible email viewer!"; // optional, comment out and test

$mail->MsgHTML($body);

$address = "user2@yahoo.co.in";
$mail->AddAddress($address, "user2");

//$mail->AddAttachment("images/phpmailer.gif");      // attachment
//$mail->AddAttachment("images/phpmailer_mini.gif"); // attachment

if(!$mail->Send()) {
  echo "Mailer Error: " . $mail->ErrorInfo;
} else {
  echo "Message sent!";
}

?>

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!";
}