$mail = new PHPMailer();
        try {
            $mail->SMTPDebug = 2;
            $mail->isSMTP();
            $mail->Host = 'smtp.myhost.com';
            $mail->SMTPAuth = true;
            $mail->Username = 'verify@mydomain.com';
            $mail->Password = 'mypass';
            $mail->SMTPSecure = false;
            $mail->Port = 25;

            //Recipients
            $mail->setFrom('verify@mydomain.com');
            $mail->addAddress('recipient@test.com');

            //Content
            $mail->isHTML(true);
            $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';

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

2018-02-27 11:05:59 SERVER -> CLIENT:
2018-02-27 11:05:59 CLIENT -> SERVER: EHLO mydomain.com
2018-02-27 11:05:59 SERVER -> CLIENT:
2018-02-27 11:05:59 SMTP ERROR: EHLO command failed:
2018-02-27 11:05:59 CLIENT -> SERVER: HELO mydomain.com
2018-02-27 11:05:59 SERVER -> CLIENT:
2018-02-27 11:05:59 SMTP ERROR: HELO command failed:
SMTP Error: Could not authenticate.
2018-02-27 11:05:59 CLIENT -> SERVER: QUIT
2018-02-27 11:05:59 SERVER -> CLIENT:
2018-02-27 11:05:59 SMTP ERROR: QUIT command failed:
SMTP connect() failed.
https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting