In Windows 7, Microsoft did not include an SMTP server as a built-in feature like in some previous versions of Windows. This means that sending emails directly using a local SMTP server is not supported out-of-the-box. However, you have a few options to work around this limitation: 1. Third-Party SMTP Servers: - You can use third-party SMTP servers like Gmail's SMTP server or others. These servers allow you to send emails through their service. - You will need to configure your PHP script to utilize the settings (like server address, port, username, password) of the third-party SMTP server for sending emails. 2. Using a Local SMTP Server Application: - Install a third-party SMTP server application on your Windows 7 machine...