A few XAMPP configuration points to send the email from PHP by using gmail account, 1, \xampp\sendmail\sendmail.ini smtp_server=smtp.gmail.com smtp_port=587 auth_username=huilin.xiong@gmail.com (your gmail account) auth_password=your passowrd 2, \xampp\php\php.ini sendmail_path = “\”D:\PHP\xampp\sendmail\sendmail.exe\” -t” 3, gmail account sign-in & security setting, set Allow less secure apps: ON If this is not set, the sending email will fail.