authentication - PHP Swift mailer: Failed to authenticate on SMTP using 2 possible authenticators

Question

When I send an email with the PHP Swift mailer to this server: smtp.exchange.example.com like this:

// Load transport
$this->transport =
    Swift_SmtpTransport::newInstance(
       self::$config->hostname,
       self::$config->port
    )
    ->setUsername(self::$config->username)
    ->setPassword(self::$config->password)
    ;

// Load mailer
$this->mailer = Swift_Mailer::newInstance($this->transport);

// Initialize message
$this->message = Swift_Message::newInstance();

// From
$this->message->setFrom(self::$config->from);

// Set message etc. ...

// Send
$this->mailer->send($this->message);

I get a strange error back:

Failed to authenticate on SMTP server with username "user@example.com" using 2 possible authenticators

I know for sure that the login-info is correct.

Answer 1

This might be old but somebody might get help through this. I too faced the same problem and received a mail on my gmail account stating that someone is trying to hack your account through an email client or a different site. THen I searched and found that doing below would resolve this issue.

Go to https://accounts.google.com/UnlockCaptcha? and unlock your account for access through other media/sites.

UPDATE : 2015

Also, you can try this, Go to https://myaccount.google.com/security#connectedapps At the bottom, towards right there is an option "Allow less secure apps". If it is "OFF", turn it on by sliding the button.

UPDATE : 2021

The google URL has now changed to : https://myaccount.google.com/lesssecureapps. You will be asked to relogin