isSMTP(); //Enable SMTP debugging //SMTP::DEBUG_OFF = off (for production use) //SMTP::DEBUG_CLIENT = client messages //SMTP::DEBUG_SERVER = client and server messages $mail->SMTPDebug = SMTP::DEBUG_CONNECTION; //Set the hostname of the mail server $mail->Host = 'smtp.example.com'; //Set the SMTP port number: // - 465 for SMTP with implicit TLS, a.k.a. RFC8314 SMTPS or // - 587 for SMTP+STARTTLS $mail->Port = 465; //Set the encryption mechanism to use: // - SMTPS (implicit TLS on port 465) or // - STARTTLS (explicit TLS on port 587) $mail->SMTPSecure = PHPMailer::ENCRYPTION_SMTPS; //Custom connection options //Note that these settings are INSECURE $mail->SMTPOptions = array( 'ssl' => [ 'verify_peer' => true, 'verify_depth' => 3, 'allow_self_signed' => true, 'peer_name' => 'smtp.example.com', 'cafile' => '/etc/ssl/ca_cert.pem', ], ); //Whether to use SMTP authentication $mail->SMTPAuth = true; //Username to use for SMTP authentication - use full email address for gmail $mail->Username = 'username@example.com'; //Password to use for SMTP authentication $mail->Password = 'yourpassword'; //Set who the message is to be sent from $mail->setFrom('from@example.com', 'First Last'); //Set who the message is to be sent to $mail->addAddress('whoto@example.com', 'John Doe'); //Set the subject line $mail->Subject = 'PHPMailer SMTP options test'; //Read an HTML message body from an external file, convert referenced images to embedded, //convert HTML into a basic plain-text alternative body $mail->msgHTML(file_get_contents('contents.html'), __DIR__); //Send the message, check for errors if (!$mail->send()) { echo 'Mailer Error: ' . $mail->ErrorInfo; } else { echo 'Message sent!'; }