in reply to
Mail Poster For website pages
Re: using a cron job...
Most mail-delivery-agents allow you to set up a "magic" mailbox to run a script as well. E.G. you might have email@example.com directed to execute your script on delivery. Examples include QMail and Procmail.
This is just a more general case that would allow "any time" changes. We used to use a QMail-triggered script to check replies to certain automatic eMails, something like the forms you send to firstname.lastname@example.org