Helo
Fatal error: Uncaught Error: Undefined constant "PHPMailer\PHPMailer\FILTER_FLAG_HOST_REQUIRED" in E:\phpwebsite\it2mailer\src\PHPMailer.php:3599 Stack trace: #0 E:\phpwebsite\it2mailer\src\PHPMailer.php(3565): PHPMailer\PHPMailer\PHPMailer::isValidHost('it2.sut.ac.th') #1 E:\phpwebsite\it2mailer\src\PHPMailer.php(2304): PHPMailer\PHPMailer\PHPMailer->serverHostname() #2 E:\phpwebsite\it2mailer\src\PHPMailer.php(1421): PHPMailer\PHPMailer\PHPMailer->createHeader() #3 E:\phpwebsite\it2mailer\src\PHPMailer.php(1316): PHPMailer\PHPMailer\PHPMailer->preSend() #4 E:\phpwebsite\it2mailer\mailtesting.php(38): PHPMailer\PHPMailer\PHPMailer->send() #5 {main} thrown in E:\phpwebsite\it2mailer\src\PHPMailer.php on line 3599