How do I make a PHP confirmation email?
Generalising, you’re asking how to store state in stateless environment. So you’ve got two choices really: store it on the server, or send it to them to send back to you. Client side, obviously you can’t put it all in a URL, much too big. You could put the info in a cookie, and that would work 99% of the time – but wouldn’t if they tried to reply later from a different computer or happened to use the non-default browser to initiate the process. Server side is probably better: send them an ID in the URL and use that to identify the reply. Where on the server? Choices are essentially: session, database or file. Session is probably too short (~25 minutes before it times out, so if they don’t reply immediately or the email takes a while, you’re dead, and has the same problem as cookies only worse as they also don’t have the same session if they close the browser in between). Database you ruled out. So store a file from PHP in a folder (outside the Web server’s name space!) named according
