How to get an email to trigger an HTTP request (or otherwise execute some function in PHP)

[eluser]ggoforth[/eluser]
On my web server which uses cPanel, I have the option (under mail forwarders) to "Pipe to existing program". This "pipes" the email to a specific PHP script that will need to parse the email and then do something with the pieces. I think this would be your best bet, as it doesn't involve polling. It will all happen as soon as the email hits the server and the server pipes the email to the waiting PHP script.

Greg