原生PHP函数mail()不适合我。它发出消息:

此邮件服务器在试图发送时需要身份验证 到非本地电子邮件地址

所以，我通常使用PHPMailer包

我已经从GitHub下载了5.2.23版本。

我只选择了2个文件，并将它们放在我的源代码PHP根目录中

class.phpmailer.php class.smtp.php

在PHP中，需要添加该文件

require_once('class.smtp.php');
require_once('class.phpmailer.php');

在此之后，它只是代码:

require_once('class.smtp.php');
require_once('class.phpmailer.php');
... 
//----------------------------------------------
// Send an e-mail. Returns true if successful 
//
//   $to - destination
//   $nameto - destination name
//   $subject - e-mail subject
//   $message - HTML e-mail body
//   altmess - text alternative for HTML.
//----------------------------------------------
function sendmail($to,$nameto,$subject,$message,$altmess)  {

  $from  = "yourcontact@yourdomain.com";
  $namefrom = "yourname";
  $mail = new PHPMailer();  
  $mail->CharSet = 'UTF-8';
  $mail->isSMTP();   // by SMTP
  $mail->SMTPAuth   = true;   // user and password
  $mail->Host       = "localhost";
  $mail->Port       = 25;
  $mail->Username   = $from;  
  $mail->Password   = "yourpassword";
  $mail->SMTPSecure = "";    // options: 'ssl', 'tls' , ''  
  $mail->setFrom($from,$namefrom);   // From (origin)
  $mail->addCC($from,$namefrom);      // There is also addBCC
  $mail->Subject  = $subject;
  $mail->AltBody  = $altmess;
  $mail->Body = $message;
  $mail->isHTML();   // Set HTML type
//$mail->addAttachment("attachment");  
  $mail->addAddress($to, $nameto);
  return $mail->send();
}

这招很管用

这是非常基本的方法发送纯文本电子邮件使用邮件功能。

<?php
$to = 'SomeOtherEmailAddress@Domain.com';
$subject = 'This is subject';
$message = 'This is body of email';
$from = "From: FirstName LastName <SomeEmailAddress@Domain.com>";
mail($to,$subject,$message,$from);

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;
}
?>

试试这个:

<?php
$to = "somebody@example.com";
$subject = "My subject";
$txt = "Hello world!";
$headers = "From: webmaster@example.com" . "\r\n" .
"CC: somebodyelse@example.com";

mail($to,$subject,$txt,$headers);
?>

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/

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';
}