使用PHPMailer通过邮件发送用户密码的步骤:

步骤1:首先，从GitHub下载PHPMailer软件包

您只需下载PHPMailer源文件并手动包含所需的文件。

您可以从PHPMailer主页[1]下载带有源代码的ZIP文件， 点击“克隆或下载”绿色按钮(右侧)，然后选择“下载ZIP”。 在要保存源文件的目录中解压缩包。

[1] https://github.com/PHPMailer/PHPMailer

第二步:打开“(来自Gmail地址)谷歌帐户”，执行以下步骤:

禁用谷歌帐号的双因素密码验证。 打开Less Security。 允许第三方应用程序。

步骤3:尝试使用下面的代码(注意:在这里，我只提供了使用PHP和MySQL通过电子邮件发送用户密码的功能代码)

    <?php 
    session_start();

    use PHPMailer\PHPMailer\PHPMailer;  //add use in starting of the code

    $db = mysqli_connect('localhost', 'root', '', '[Enter your Database Name]'); // connect to database

    if (isset($_POST['forgot_btn'])) {
        forgotpassword();
    }

    function forgotpassword(){
    global $db;
     
        $user_id = $_POST['user_id'];
        $result = mysqli_query($db,"SELECT * FROM users where user_id='$user_id'");
        $row = mysqli_fetch_assoc($result);
        $fetch_user_id=$row['user_id'];
        $name=$row['name'];
        $email_id=$row['email_id'];
        $password=$row['password'];
        if($user_id==$fetch_user_id) {
       require '../PHPMailer/vendor/autoload.php';  //Please correctly mention the PHPMailer installed directory (Don't follow my directory)

    $mail = new PHPMailer(TRUE);
    try{
       $mail->setFrom('[Enter your From Email_Address]', '[Enter Sender Name]');
       $mail->addAddress($email_id, $name);  //[To Email Address and Name]
       $mail->Subject = 'Regarding Forgot Password';
       $mail->Body = 'Hi '.$name.',Your Login Password is:'.$password.'';
       $mail->isSMTP();
       $mail->Host = 'smtp.gmail.com';
       $mail->SMTPAuth = TRUE;
       $mail->SMTPSecure = 'tls';
       $mail->Username = '[Enter your From Email_Address]';
       $mail->Password = '[Enter your From Email_Address -> Password]';
       $mail->Port = 587;
       
       if($mail->send())
       {
          echo "<script>alert('Password Sent Successfully');</script>"; 
       }
       else
       {
         echo "<script>alert('Please Check Your Internet Connection or From Email Address/Password or Wrong To Email Address');</script>";   
       }
    }
    catch (Exception $e)
    {
       echo "<script>alert('Please Check Your Internet Connection or From Email Address/Password or Wrong To Email Address');</script>";
    }
        }
    }

    ?>

更多信息请参考这些文档[1]:

[1]. https://alexwebdevelop.com/phpmailer-tutorial/

还可以查看PEAR邮件包PEAR mail Page

它似乎比内置的标准mail()函数健壮一些(如果标准函数不够的话)。

下面是该页面的一段摘录，展示如何使用它。PEAR邮件发送()用法

<?php
    include('Mail.php');

    $recipients = 'joe@example.com';

    $headers['From']    = 'richard@example.com';
    $headers['To']      = 'joe@example.com';
    $headers['Subject'] = 'Test message';

    $body = 'Test message';

    $smtpinfo["host"] = "smtp.server.com";
    $smtpinfo["port"] = "25";
    $smtpinfo["auth"] = true;
    $smtpinfo["username"] = "smtp_user";
    $smtpinfo["password"] = "smtp_password";


    // Create the mail object using the Mail::factory method
    $mail_object =& Mail::factory("smtp", $smtpinfo); 

    $mail_object->send($recipients, $headers, $body);
?> 

你也可以在https://github.com/PHPMailer/PHPMailer上使用PHPMailer类。

它允许您使用邮件功能或透明地使用smtp服务器。它还可以处理基于HTML的电子邮件和附件，因此您不必编写自己的实现。

这个类是稳定的，它被许多其他项目使用，如Drupal、SugarCRM、Yii和Joomla!

下面是上面页面的一个例子:

<?php
require 'PHPMailerAutoload.php';

$mail = new PHPMailer;

$mail->isSMTP();                                      // Set mailer to use SMTP
$mail->Host = 'smtp1.example.com;smtp2.example.com';  // Specify main and backup SMTP servers
$mail->SMTPAuth = true;                               // Enable SMTP authentication
$mail->Username = 'user@example.com';                 // SMTP username
$mail->Password = 'secret';                           // SMTP password
$mail->SMTPSecure = 'tls';                            // Enable encryption, 'ssl' also accepted

$mail->From = 'from@example.com';
$mail->FromName = 'Mailer';
$mail->addAddress('joe@example.net', 'Joe User');     // Add a recipient
$mail->addAddress('ellen@example.com');               // Name is optional
$mail->addReplyTo('info@example.com', 'Information');
$mail->addCC('cc@example.com');
$mail->addBCC('bcc@example.com');

$mail->WordWrap = 50;                                 // Set word wrap to 50 characters
$mail->addAttachment('/var/tmp/file.tar.gz');         // Add attachments
$mail->addAttachment('/tmp/image.jpg', 'new.jpg');    // Optional name
$mail->isHTML(true);                                  // Set email format to HTML

$mail->Subject = 'Here is the subject';
$mail->Body    = 'This is the HTML message body <b>in bold!</b>';
$mail->AltBody = 'This is the body in plain text for non-HTML mail clients';

if(!$mail->send()) {
    echo 'Message could not be sent.';
    echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
    echo 'Message has been sent';
}

<?php
include "db_conn.php";//connection file
require "PHPMailerAutoload.php";// it will be in PHPMailer
require "class.smtp.php";// it will be in PHPMailer
require "class.phpmailer.php";// it will be in PHPMailer


$response = array();
$params = json_decode(file_get_contents("php://input"));

if(!empty($params->email_id)){

    $email_id = $params->email_id;
    $flag=false;
    echo "something";
    if(!filter_var($email_id, FILTER_VALIDATE_EMAIL))
    {
        $response['ERROR']='EMAIL address format error'; 
        echo json_encode($response,JSON_UNESCAPED_SLASHES);
        return;
    }
    $sql="SELECT * from sales where email_id ='$email_id' ";

    $result = mysqli_query($conn,$sql);
    $count = mysqli_num_rows($result);

    $to = "demo@gmail.com";
    $subject = "DEMO Subject";
    $messageBody ="demo message .";

    if($count ==0){
        $response["valid"] = false;
        $response["message"] = "User is not registered yet";
        echo json_encode($response);
        return;
    }

    else {

        $mail = new PHPMailer();
        $mail->IsSMTP();
        $mail->SMTPAuth = true; // authentication enabled
        $mail->IsHTML(true); 
        $mail->SMTPSecure = 'ssl';//turn on to send html email
        // $mail->Host = "ssl://smtp.zoho.com";
        $mail->Host = "p3plcpnl0749.prod.phx3.secureserver.net";//you can use gmail 
        $mail->Port = 465;
        $mail->Username = "demousername@example.com";
        $mail->Password = "demopassword";
        $mail->SetFrom("demousername@example.com", "Any demo alert");
        $mail->Subject = $subject;

        $mail->Body = $messageBody;
        $mail->AddAddress($to);
        echo "yes";

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

}
else{
    $response["valid"] = false;
    $response["message"] = "Required field(s) missing";
    echo json_encode($response);
}


?>

上面的代码为我工作。

完整的代码示例..

试一次…

<?php
// Multiple recipients
$to = 'johny@example.com, sally@example.com'; // note the comma

// Subject
$subject = 'Birthday Reminders for August';

// Message
$message = '
<html>
<head>
  <title>Birthday Reminders for August</title>
</head>
<body>
  <p>Here are the birthdays upcoming in August!</p>
  <table>
    <tr>
      <th>Person</th><th>Day</th><th>Month</th><th>Year</th>
    </tr>
    <tr>
      <td>Johny</td><td>10th</td><td>August</td><td>1970</td>
    </tr>
    <tr>
      <td>Sally</td><td>17th</td><td>August</td><td>1973</td>
    </tr>
  </table>
</body>
</html>
';

// To send HTML mail, the Content-type header must be set
$headers[] = 'MIME-Version: 1.0';
$headers[] = 'Content-type: text/html; charset=iso-8859-1';

// Additional headers
$headers[] = 'To: Mary <mary@example.com>, Kelly <kelly@example.com>';
$headers[] = 'From: Birthday Reminder <birthday@example.com>';
$headers[] = 'Cc: birthdayarchive@example.com';
$headers[] = 'Bcc: birthdaycheck@example.com';

// Mail it
mail($to, $subject, $message, implode("\r\n", $headers));
?>

对于未来的读者:如果其他答案都不管用(就像我的情况一样)，试试这个:

1)。下载PHPMailer，打开zip文件并解压到您的项目目录。

3)。将提取的目录重命名为phpailer，并在php脚本中编写以下代码(脚本必须在phpailer文件夹之外)

<?php
// PHPMailer classes into the global namespace
use PHPMailer\PHPMailer\PHPMailer; 
use PHPMailer\PHPMailer\Exception;
// Base files 
require 'PHPMailer/src/Exception.php';
require 'PHPMailer/src/PHPMailer.php';
require 'PHPMailer/src/SMTP.php';
// create object of PHPMailer class with boolean parameter which sets/unsets exception.
$mail = new PHPMailer(true);                              
try {
    $mail->isSMTP(); // using SMTP protocol                                     
    $mail->Host = 'smtp.gmail.com'; // SMTP host as gmail 
    $mail->SMTPAuth = true;  // enable smtp authentication                             
    $mail->Username = 'sender@gmail.com';  // sender gmail host              
    $mail->Password = 'password'; // sender gmail host password                          
    $mail->SMTPSecure = 'tls';  // for encrypted connection                           
    $mail->Port = 587;   // port for SMTP     

    $mail->setFrom('sender@gmail.com', "Sender"); // sender's email and name
    $mail->addAddress('receiver@gmail.com', "Receiver");  // receiver's email and name

    $mail->Subject = 'Test subject';
    $mail->Body    = 'Test body';

    $mail->send();
    echo 'Message has been sent';
} catch (Exception $e) { // handle error.
    echo 'Message could not be sent. Mailer Error: ', $mail->ErrorInfo;
}
?>