How can PHP scripts be set up to run in the background without requiring the browser to stay open during mass-mail optimization?

To run PHP scripts in the background without requiring the browser to stay open, you can use the `exec()` function to execute the script from the command line. This allows the script to run independently of the browser, making it suitable for tasks like mass-mail optimization. Additionally, you can use `nohup` to ensure the script continues running even after the terminal session is closed.

// Execute PHP script in the background using exec()
exec('nohup php /path/to/script.php > /dev/null 2>&1 &');