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_SmtpTra         


        

Answer 1

I got the same same error.

I was using gmail account and Google's SMTP server to send emails. The problem was due to SMTP server refusing to authorize as it considered my web host (through whom I sent email) as an intruder.

I followed Google's process to identify my web host as an valid entity to send email through my account and problem was solved.