PHP uses pear_smtp to send emails. Send emails regularly. Python sends emails. Outlook sends emails regularly.

The mail function that comes with PHP is a pain in the ass. Even after configuring sendmail under win, I still cannot send emails. Using third-party pear/mail can directly connect to the mail sending server through SMTP. Such as (smtp.163.com). There is no need to install sendmail or other similar software on this machine.
Make sure the PEAR Mail package is installed.

"; 
 $to = "test <test>"; 
 $subject = "Hi!"; 
 $body = "Hi,\n\nHow are you?"; 
  
 $host = "smtp.163.com"; 
$port = "25"; 
 $username = "test@163.com"; 
 $password = "test123"; 
  
 $headers = array ('From' => $from, 
  'To' => $to, 
  'Subject' => $subject); 
 $smtp = Mail::factory('smtp', 
  array ('host' => $host, 
   'port' => $port, 
   'auth' => true, 
  // 'debug'=>true, 
   'username' => $username, 
   'password' => $password)); 
  
 $mail = $smtp->send($to, $headers, $body); 
  
 if (PEAR::isError($mail)) { 
  echo("<p>" . $mail->getMessage() . "</p>"); 
 } else { 
  echo("<p>Message successfully sent!</p>"); 
 } 
 ?>
</test>

This is a non-encrypted method.
Most of PHPer uses the mail function to send emails, but we can use other SMTP servers to send emails. It is recommended to use PEAR's mail package to send emails.

 $subject = "This mail is sent from SMTP.";
$mail_body = "This is the body of the mail which is sent using SMTP.";
$from = "From: From Name <fromaddress>"; 
$to = "To: To Name <toaddress>"; 
$receiver = "toaddress@xpertdeveloper.com"; 
 
// Setting up the headers
$headers["From"] = $from; 
$headers["To"] = $to; 
$headers["Subject"] = $subject; 
$headers["Reply-To"] = "reply@address.com"; 
$headers["Content-Type"] = "text/plain; charset=ISO-2022-JP"; 
$headers["Return-path"] = "returnpath@address.com"; 
 
// Setting up the SMTP setting
$smtp_info["host"] = "smtp.server.com"; 
$smtp_info["port"] = "25"; 
$smtp_info["auth"] = true; 
$smtp_info["username"] = "smtp_user"; 
$smtp_info["password"] = "smtp_password"; 
 
// Creating the PEAR mail object :
$mail_obj =& Mail::factory("smtp", $smtp_info); 
 
// Sending the mail now
$mail_sent = $mail_obj->send($receiver, $headers, $mail_body); 
 
// If any error the see for that here:
if (PEAR::isError($mail_sent)) { print($mail_sent->getMessage());}
</toaddress></fromaddress>

The third case:

Before using the following source code, please configure the path of pear and download the net_smtp package
Choose different setting methods in the php.ini file according to your operating system

; UNIX: "/path1:/path2" 
include_path = ".:./php/pear"
;
; Windows: "\path1;\path2"
;include_path = ".;c:\php\pear"
require 'Net/SMTP.php';
$host = '126.com';//smtp服务器的ip或域名
$username= 'arcow';//登陆smtp服务器的用户名
$password= 'secret';//登陆smtp服务器的密码
$from = 'arcow@126.com';  //谁发的邮件
$rcpt = array('test@test.com', 'arcow@126.com');//可设多个接收者
$subj = "Subject: 你是谁\n";//主题
$body = "test it";//邮件内容
/* 建立一个类 */
if (! ($smtp = new Net_SMTP($host))) {
  die("无法初始化类Net_SMTP!\n");
}
/* 开始连接SMTP服务器*/
if (PEAR::isError($e = $smtp->connect())) {
  die($e->getMessage() . "\n");
}
/* smtp需要身份验证 */
$smtp->auth($username,$password,"PLAIN");
/*设置发送者邮箱 */
if (PEAR::isError($smtp->mailFrom($from))) {
  die("无法设置发送者邮箱为 \n");
}
/* 设置接收邮件者 */
foreach ($rcpt as $to) {
  if (PEAR::isError($res = $smtp->rcptTo($to))) {
    die("邮件无法投递到 : " . $res->getMessage() . "\n");
  }
}
/* 开始发送邮件内容 */
if (PEAR::isError($smtp->data($subj . "\r\n" . $body))) {
  die("Unable to send data\n");
}
/* 断开连接 */
$smtp->disconnect();
echo "发送成功！";
?>

The above is the entire content of this article. Three cases of PHP using pear_smtp to send emails. I hope it will be helpful to everyone in learning PHP programming.

The above introduces how PHP uses pear_smtp to send emails, including sending emails and pear content. I hope it will be helpful to friends who are interested in PHP tutorials.