How to use PHPMailer to send an Email via Gmail SMTP Server?

There is a simple mail function in PHP to send emails.

Why to use PHPMailer library then?

Because mail function in PHP doesn’t provide attachments. Some other features like authentication, encryption or HTML messages are very well crafted in PHPMailer.

It has an integrated SMTP client so that you don’t need to use a local mail server. It’s helpful for platforms like Pantheon that don’t have a local mail server support.

Alternatively you can use libraries like ZetaComponents, SwiftMailer or Laminas/Mail. They all are very good options for secure email delivery.

How to install it?

You can use composer to install it.

Just add this code to your composer.json


"phpmailer/phpmailer": "^6.2"

or install it using terminal


composer require phpmailer/phpmailer

What if you don’t want to use composer?

Then just download PHPMailer as a zip file.

After downloading the zip file, you need to copy the PHPMailer folder contents into one of the include_path directories in your PHP config.

One that’s done, add this code to load each class file manually in PHP file.


use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

require 'path/to/PHPMailer/src/Exception.php';
require 'path/to/PHPMailer/src/PHPMailer.php';
require 'path/to/PHPMailer/src/SMTP.php';

Don’t use the last like SMTP if you’re not using the SMTP class. Since this example is about Gmail SMTP I have included that line.

A Simple Example

Add this code to your PHP file using which you want to send the email and change the values accordingly.


//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\SMTP;
use PHPMailer\PHPMailer\Exception;

//Load Composer's autoloader
require 'vendor/autoload.php';

//Instantiation and passing `true` enables exceptions
$mail = new PHPMailer(true);

try {
    //Server settings
    $mail->SMTPDebug = SMTP::DEBUG_SERVER;                      //Enable verbose debug output
    $mail->isSMTP();                                            //Send using SMTP
    $mail->Host       = 'smtp.example.com';                     //Set the SMTP server to send through
    $mail->SMTPAuth   = true;                                   //Enable SMTP authentication
    $mail->Username   = '[email protected]';                     //SMTP username
    $mail->Password   = 'secret';                               //SMTP password
    $mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;         //Enable TLS encryption; `PHPMailer::ENCRYPTION_SMTPS` encouraged
    $mail->Port       = 587;                                    //TCP port to connect to, use 465 for `PHPMailer::ENCRYPTION_SMTPS` above

    //Recipients
    $mail->setFrom('[email protected]', 'Mailer');
    $mail->addAddress('[email protected]', 'Joe User');     //Add a recipient
    $mail->addAddress('[email protected]');               //Name is optional
    $mail->addReplyTo('[email protected]', 'Information');
    $mail->addCC('[email protected]');
    $mail->addBCC('[email protected]');

    //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 = 'Here is the subject';
    $mail->Body    = 'This is the HTML message body in bold!';
    $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}";
}

Gmail SMTP Example


/**
 * This example shows settings to use when sending via Google's Gmail servers.
 * This uses traditional id & password authentication - look at the gmail_xoauth.phps
 * example to see how to use XOAUTH2.
 * The IMAP section shows how to save this message to the 'Sent Mail' folder using IMAP commands.
 */

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

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_SERVER;

//Set the hostname of the mail server
$mail->Host = 'smtp.gmail.com';
//Use `$mail->Host = gethostbyname('smtp.gmail.com');`
//if your network does not support SMTP over IPv6,
//though this may cause issues with TLS

//Set the SMTP port number - 587 for authenticated TLS, a.k.a. RFC4409 SMTP submission
$mail->Port = 587;

//Set the encryption mechanism to use - STARTTLS or SMTPS
$mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;

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

//Username to use for SMTP authentication - use full email address for gmail
$mail->Username = '[email protected]';

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

//Set who the message is to be sent from
$mail->setFrom('[email protected]', 'First Last');

//Set an alternative reply-to address
$mail->addReplyTo('[email protected]', 'First Last');

//Set who the message is to be sent to
$mail->addAddress('[email protected]', 'John Doe');

//Set the subject line
$mail->Subject = 'PHPMailer GMail SMTP 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__);

//Replace the plain text body with one created manually
$mail->AltBody = 'This is a plain-text message body';

//Attach an image file
$mail->addAttachment('images/phpmailer_mini.png');

//send the message, check for errors
if (!$mail->send()) {
    echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
    echo 'Message sent!';
    //Section 2: IMAP
    //Uncomment these to save your message in the 'Sent Mail' folder.
    #if (save_mail($mail)) {
    #    echo "Message saved!";
    #}
}

//Section 2: IMAP
//IMAP commands requires the PHP IMAP Extension, found at: https://php.net/manual/en/imap.setup.php
//Function to call which uses the PHP imap_*() functions to save messages: https://php.net/manual/en/book.imap.php
//You can use imap_getmailboxes($imapStream, '/imap/ssl', '*' ) to get a list of available folders or labels, this can
//be useful if you are trying to get this working on a non-Gmail IMAP server.
function save_mail($mail)
{
    //You can change 'Sent Mail' to any other folder or tag
    $path = '{imap.gmail.com:993/imap/ssl}[Gmail]/Sent Mail';

    //Tell your server to open an IMAP connection using the same username and password as you used for SMTP
    $imapStream = imap_open($path, $mail->Username, $mail->Password);

    $result = imap_append($imapStream, $path, $mail->getSentMIMEMessage());
    imap_close($imapStream);

    return $result;
}

Read more about it on PHPMailer Github repo.

class email github library PHPMailer

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