Send a mail via SMTP using PHP

<?php
require 'email.class.php';
$mailto='***';
$mailsubject="Test mail";
$mailbody='Here is the mail content';
$smtpserver     = "smtpdm.aliyun.com";
$smtpserverport = 25;
$smtpusermail   = "***";
$smtpuser       = "***";
$smtppass       = "***";
$mailsubject    = "=?UTF-8?B?" . base64_encode($mailsubject) . "?=";
$mailtype       = "HTML";
$smtp           = new smtp($smtpserver, $smtpserverport, true, $smtpuser, $smtppass);
$smtp->debug    = false;
$smtp->sendmail($mailto, $smtpusermail, $mailsubject, $mailbody, $mailtype);

Note: email.class.php is an external dependency which you should obtain by yourself. smtpuser =“Replace it with the complete sender address”.