PHPMailer/examples/ssl_options.phps

<?php

/**
 * This example shows settings to use when sending over SMTP with TLS and custom connection options.
 */

//Import the PHPMailer class into the global namespace
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\SMTP;

//SMTP needs accurate times, and the PHP time zone MUST be set
//This should be done in your php.ini, but this is how to do it if you don't have access to that
date_default_timezone_set('Etc/UTC');

require '../vendor/autoload.php';

//Create a new PHPMailer instance
$mail = new PHPMailer();

//Tell PHPMailer to use SMTP
$mail->isSMTP();

//Enable SMTP debugging
//SMTP::DEBUG_OFF = off (for production use)
//SMTP::DEBUG_CLIENT = client messages
//SMTP::DEBUG_SERVER = client and server messages
$mail->SMTPDebug = SMTP::DEBUG_CONNECTION;

//Set the hostname of the mail server
$mail->Host = 'smtp.example.com';

//Set the SMTP port number:
// - 465 for SMTP with implicit TLS, a.k.a. RFC8314 SMTPS or
// - 587 for SMTP+STARTTLS
$mail->Port = 465;

//Set the encryption mechanism to use:
// - SMTPS (implicit TLS on port 465) or
// - STARTTLS (explicit TLS on port 587)
$mail->SMTPSecure = PHPMailer::ENCRYPTION_SMTPS;

//Custom connection options
//Note that these settings are INSECURE
$mail->SMTPOptions = array(
    'ssl' => [
        'verify_peer' => true,
        'verify_depth' => 3,
        'allow_self_signed' => true,
        'peer_name' => 'smtp.example.com',
        'cafile' => '/etc/ssl/ca_cert.pem',
    ],
);

//Whether to use SMTP authentication
$mail->SMTPAuth = true;

//Username to use for SMTP authentication - use full email address for gmail
$mail->Username = 'username@example.com';

//Password to use for SMTP authentication
$mail->Password = 'yourpassword';

//Set who the message is to be sent from
$mail->setFrom('from@example.com', 'First Last');

//Set who the message is to be sent to
$mail->addAddress('whoto@example.com', 'John Doe');

//Set the subject line
$mail->Subject = 'PHPMailer SMTP options test';

//Read an HTML message body from an external file, convert referenced images to embedded,
//convert HTML into a basic plain-text alternative body
$mail->msgHTML(file_get_contents('contents.html'), __DIR__);

//Send the message, check for errors
if (!$mail->send()) {
    echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
    echo 'Message sent!';
}