如何通过电子邮件控制Web应用程序？或者如何通过发送电子邮件运行PHP脚本？

I want to run a web application on php and mysql, using the CakePHP framework. And to keep the threshold of using the site at a very low place, I want to not use the standard login with username/password. (And I don't want to hassle my users with something like OpenID either. Goes to user type.)I want to run a web application on php and mysq