Unable to send email using Gmail SMTP server through PHPMailer, getting error: SMTP AUTH is required for message submission on port 587. How to fix?

Question

I would like to send an email using Gmail SMTP server through PHP Mailer.

this is my code

Answer 1

Open this Link and select follow the instructions google servers blocks any attempts from unknown servers so once you click on captcha check every thing will be fine

Answer 2

 $mail->SMTPOptions = array(
                'ssl' => array(
                    'verify_peer' => false,
                    'verify_peer_name' => false,
                    'allow_self_signed' => true
                )
            );

Answer 3

Google treat Gmail accounts differently depending on the available user information, probably to curb spammers.

I couldn't use SMTP until I did the phone verification. Made another account to double check and I was able to confirm it.

Answer 4

Anderscc has got it correct. Thanks. It worked for me but not 100%.

I had to set

$mail->SMTPDebug = 0;

Setting it to 1, can cause errors especially if you are passing some data as json to next page. Example - Performing verification if mail is sent, using json to pass data through ajax.

I had to lower my gmail account security settings to get rid of errors: " SMTP connect() failed " and " SMTP ERROR: Password command failed "

Solution: This problem can be caused by either 'less secure' applications trying to use the email account (this is according to google help, not sure how they judge what is secure and what is not) OR if you are trying to login several time in a row OR if you change countries (for example use VPN, move code to different server or actually try to login from different part of the world).

Links that fix the problem (you must be logged into google account):

• view recent attempts to use the account and accept suspicious access.

• link to disable the feature of blocking suspicious apps/technologies:

  https://www.google.com/settings/u/1/security/lesssecureapps

Note: You can go to the following stackoverflow answer link for more detailed reference.

https://stackoverflow.com/a/25175234

Answer 5

If you are using cPanel you should just click the wee box that allows you to send to external servers by SMTP.

Login to CPanel > Tweak Settings > All> "Restrict outgoing SMTP to root, exim, and mailman (FKA SMTP Tweak)"

As answered here:

"Password not accepted from server: 535 Incorrect authentication data" when sending with GMail and phpMailer

Answer 6

this code working fine for me

    $mail = new PHPMailer;
    //Enable SMTP debugging. 
    $mail->SMTPDebug = 0;
    //Set PHPMailer to use SMTP.
    $mail->isSMTP();
    //Set SMTP host name                          
    $mail->Host = $hostname;
    //Set this to true if SMTP host requires authentication to send email
    $mail->SMTPAuth = true;
    //Provide username and password     
    $mail->Username = $sender;
    $mail->Password = $mail_password;
    //If SMTP requires TLS encryption then set it
    $mail->SMTPSecure = "ssl";
    //Set TCP port to connect to 
    $mail->Port = 465;
    $mail->From = $sender;  
    $mail->FromName = $sender_name;
    $mail->addAddress($to);
    $mail->isHTML(true);
    $mail->Subject = $Subject;
    $mail->Body = $Body;
    $mail->AltBody = "This is the plain text version of the email content";
    if (!$mail->send()) {
        echo "Mailer Error: " . $mail->ErrorInfo;
    }
    else {
           echo 'Mail Sent Successfully';
    }