mail.php

<?php
// Import PHPMailer classes into the global namespace
// These must be at the top of your script, not inside a function
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

//Load Composer's autoloader
require 'PHPMailer/src/Exception.php';
require 'PHPMailer/src/PHPMailer.php';
require 'PHPMailer/src/SMTP.php';
function mailSend($email,$subject,$body){
    $mail = new PHPMailer(true);                              // Passing `true` enables exceptions
    try {
        //Server settings
        $mail->SMTPDebug = 0;                                 // Enable verbose debug output
        $mail->isSMTP();                                      // Set mailer to use SMTP
        $mail->Host = 'smtp.gmail.com';  // Specify main and backup SMTP servers
        $mail->SMTPAuth = true;                               // Enable SMTP authentication
        $mail->Username = 'php1803lm@gmail.com';                 // SMTP username
        $mail->Password = 'Qaz@@123';                           // SMTP password
        $mail->SMTPSecure = 'tls';                            // Enable TLS encryption, `ssl` also accepted
        $mail->Port = 587;     
        $mail -> charSet = "UTF-8";                               // TCP port to connect to

        //Recipients
        $mail->setFrom('testmail@gmail.com', 'Cua hang');
        $mail->addAddress($email, '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');

        //Attachments
        // $mail->addAttachment('/var/tmp/file.tar.gz');         // Add attachments
        // $mail->addAttachment('/tmp/image.jpg', 'new.jpg');    // Optional name

        //Content
        $mail->isHTML(true);                                  // Set email format to HTML
        $mail->Subject = $subject;
        $mail->Body    = $body;
        // $mail->AltBody = 'This is the body in plain text for non-HTML mail clients';

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