I know this is an old question but it's still active and all the answers I saw showed basic authentication, which is deprecated. Here is an example showing how to send email using SMTP via Google's Gmail servers using PHPMailer with XOAUTH2 authentication:
//Import PHPMailer classes into the global namespace use PHPMailer\PHPMailer\PHPMailer; use PHPMailer\PHPMailer\SMTP; use PHPMailer\PHPMailer\OAuth; //Alias the League Google OAuth2 provider class use League\OAuth2\Client\Provider\Google; //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'); //Load dependencies from composer //If this causes an error, run 'composer install' 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'; //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; //Whether to use SMTP authentication $mail->SMTPAuth = true; //Set AuthType to use XOAUTH2 $mail->AuthType = 'XOAUTH2'; //Fill in authentication details here //Either the gmail account owner, or the user that gave consent $email = '[email protected]'; $clientId = 'RANDOMCHARS-----duv1n2.apps.googleusercontent.com'; $clientSecret = 'RANDOMCHARS-----lGyjPcRtvP'; //Obtained by configuring and running get_oauth_token.php //after setting up an app in Google Developer Console. $refreshToken = 'RANDOMCHARS-----DWxgOvPT003r-yFUV49TQYag7_Aod7y0'; //Create a new OAuth2 provider instance $provider = new Google( [ 'clientId' => $clientId, 'clientSecret' => $clientSecret, ] ); //Pass the OAuth provider instance to PHPMailer $mail->setOAuth( new OAuth( [ 'provider' => $provider, 'clientId' => $clientId, 'clientSecret' => $clientSecret, 'refreshToken' => $refreshToken, 'userName' => $email, ] ) ); //Set who the message is to be sent from //For gmail, this generally needs to be the same as the user you logged in as $mail->setFrom($email, '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 XOAUTH2 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->CharSet = PHPMailer::CHARSET_UTF8; $mail->msgHTML(file_get_contents('contentsutf8.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!'; }
Reference: PHPMailer examples folder
