Locate the sender of an email and their geographical location, including messages sent through anonymous email services like Gmail, Yahoo, and Hotmail.

Software

Secure phpinfo.php with .htaccess, Now instead of getting a 404 error you will see debug information which will help you find out what the problem is.

PHP

If you examine the preferences dialog of any modern Web browser (like Internet Explorer, Safari or Mozilla), you'll probably notice a 'cache' setting. This lets you set aside a section of your computer's hard disk to store representations that you've seen, just for you. The browser cache works according to fairly simple rules. It will check to make sure that the representations are fresh, usually once a session (that is, the once in the current invocation of the browser).

Optimization