SMTP Error: Could not authenticate. Message could not be sent. Mailer Error: SMTP Error: Could not authenticate

Question

When I trying to send a email using PHP SMTP email server, following error has occurred.

SMTP Error: Could not authenticate. Message could not be sent.

Mailer Error: SMTP Error: Could not authenticate.

---

Following is my code that I have used.

function supervisorMail(){

global $error;
$mail = new PHPMailer();
$mail->IsSMTP();
$mail->SMTPDebug = 0;
$mail->SMTPAuth = true;
$mail->SMTPSecure = 'ssl';
$mail->Host = 'smtp.gmail.com';
$mail->Port = 465;
$mail->Username = "***@gmail.com";
$mail->Password = "****";
$mail->SetFrom("***@gmail.com", "Employee Leave Management System");

$userID=$_SESSION['userID'];

$select_query = mysql_query("SELECT * FROM employee WHERE emp_id = '$userID'");
$select_sql = mysql_fetch_array($select_query);
$name=$select_sql['manager_name'];
var_dump($name);

$select_query1 = mysql_query("SELECT email FROM employee WHERE emp_id='$name'");
$select_sql1 = mysql_fetch_array($select_query1);
$email=$select_sql1['email'];
    var_dump($email);

$mail->Subject = "subject ";
$mail->Body = "something.";
$mail_to = $email;
$mail->AddAddress($mail_to);

if(!$mail->Send())
{
    echo "Message could not be sent. <p>";
    echo "Mailer Error: " . $mail->ErrorInfo;
    exit;
}

echo "Message has been sent";

}

How can I fixed this error.

Answer 1

The error message is very clear "Could not authenticate". I would say you are correctly using the PHPMailer class, but just not filling in the correct gmail account details.

I suppose that in your question the fields username and password look like

$mail->Username = "@gmail.com";
$mail->Password = "";

just because you, obviously, don't want to share them, I would suggest to present them like this in the question

$mail->Username = "********@gmail.com";
$mail->Password = "********";

So if you are using the correct username and password there are other two things to check

1. Maybe your setting "Access for less secure apps" is turned off. After you login from the web you can turn it on from this page https://www.google.com/settings/u/0/security/lesssecureapps

2. If that is On, it might be possible you have 2-Step Verification enabled in your gmail account. If this is the case, you need to create an App specific password.

Follow this link for a step by step guide on how to do it http://email.about.com/od/gmailtips/fl/How-to-Get-a-Password-to-Access-Gmail-By-POP-or-IMAP.htm

Answer 2

Please unable your less secure app and then Try to comment this line

//$mail->IsSMTP();

I hope it will work!

Answer 3

You may try to use google app password for authentication:

https://support.google.com/accounts/answer/185833?hl=en

1. 2-Step-Verification & 2. App Passwords

Answer 4

As mentioned in comment, you need to enter valid gmail id and password.

Please refer below demo code.

<?php
require 'PHPMailer/PHPMailerAutoload.php';
$mail = new PHPMailer;
$mail->SMTPDebug = 2;    // 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 = '*****001@gmail.com';  // SMTP username
$mail->Password = 'ma****02';    // SMTP password
$mail->SMTPSecure = 'tls'; // Enable TLS encryption, `ssl` also accepted
$mail->Port = 465; // TCP port to connect to
$mail->setFrom('ravi******@gmail.com', 'Mailer'); // Add set from id
$mail->addAddress('er.ravihirani@gmail.com', 'Ravi Hirani');     // Add a recipient
//$mail->addAddress('ellen@example.com');               // Name is optional
//$mail->addReplyTo('info@example.com', 'Information');
//$mail->addCC('cc@example.com');
//$mail->addBCC('bcc@example.com');
//$mail->addAttachment('/var/tmp/file.tar.gz');         // Add attachments
//$mail->addAttachment('/tmp/image.jpg', 'new.jpg');    // Optional name
//$mail->isHTML(true);   // Set email format to HTML
$mail->Subject = 'Here is the subject';
$mail->Body    = 'This is the HTML message body <b>in bold!</b>';
$mail->AltBody = 'This is the body in plain text for non-HTML mail clients';
if(!$mail->send()) {
    echo 'Message could not be sent.';
    echo 'Mailer Error: ' . $mail->ErrorInfo;
} else {
    echo 'Message has been sent';
}

Answer 5

I ran into this error message and wanted to post an answer in case it can help someone else. I have phpmailer installed with composer and am running php 7. The implementation of the phpmailer script that threw the error is in a php object method. The password variable, set in a config file elsewhere, needed to be declared as a global in the object context otherwise it did not contain the actual password and thus caused the authentication error..

        global $password; // <- this added to make script work

        $mail = new PHPMailer(true);   
        try {
            $mail->isSMTP();            

            // Set mailer to use SMTP               
            $mail->Host = '*******.com'; 
            $mail->SMTPAuth = true;   
            $mail->Username = 'no-reply@*******.com'; 
            $mail->Password = $password;     
            $mail->SMTPSecure = 'tls';      
            $mail->Port = 587;        
            $mail->setFrom('no-reply@*******.com', '******* - DO NOT REPLY'); 

            //$mail->isHTML(true);  
            $mail->AddAddress($user->email);

            $mail->Subject = "*******";
            $mail->Body    = "*******";

            $mail->send();

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

Answer 6

In my case it was because I didn't turn on the Less secure app access from here: https://myaccount.google.com/lesssecureapps