"SMTP Error: Could not authenticate" in PHPMailer

Question

I'm using PHPMailer in a Simple Script For Send Email's Through Gmail, and I'm getting an "Unknown Error" (At least for me!):

SMTP Error: Could not authenticate. Error: SMTP Error: Could not authenticate.

SMTP server error: 5.7.1 Username and Password not accepted. Learn more at 535 5.7.1 http://mail.google.com/support/bin/answer.py?answer=14257 p38sm2467302ybk.16

I've read about Configure OpenSSL For SSL/TLS Connections, and I did it. Apache And PHP Are properly-Configured (With OpenSSL extension Running in PHP and mod_ssl running in Apache 2.2.16).

This is The PHP Script:

 <?php   require_once ("PHPMailer\class.phpmailer.php");   $Correo = new PHPMailer();   $Correo->IsSMTP();   $Correo->SMTPAuth = true;   $Correo->SMTPSecure = "tls";   $Correo->Host = "smtp.gmail.com";   $Correo->Port = 587;   $Correo->UserName = "[email protected]";   $Correo->Password = "gmailpassword";   $Correo->SetFrom('[email protected]','De Yo');   $Correo->FromName = "From";   $Correo->AddAddress("[email protected]");   $Correo->Subject = "Prueba con PHPMailer";   $Correo->Body = "<H3>Bienvenido! Esto Funciona!</H3>";   $Correo->IsHTML (true);   if (!$Correo->Send())   {     echo "Error: $Correo->ErrorInfo";   }   else   {     echo "Message Sent!";   } ?> 

The Username and Password are OK, And I tried in Thunderbird, without any problem. I've also Used SSL Authentication and Port 465, getting the same Error.

Answer 1

I encountered this problem. To get it working, I had to go to myaccount.google.com -> "Sign-in & security" -> "Apps with account access", and turn "Allow less secure apps" to "ON" (near the bottom of the page).

Alternatively you can follow this direct link to these settings