Do any of the popular hosting services (e.g., 1and1, GoDaddy, etc) offer a way to execute a script as a response to an email? I'd like to be able to parse emails sent to my domain and send back a response.
you need to redirect your emails to your script. It is easy to do if you have root access. But some control panels are able to handle it too. For example in Cpanel control panel you can use the option forwarding for an email account, instead of delivering to an email address you put a full path to your script, so you can parse emails by a script and send back a response. for example hostingrow.com provides Cpanel control panel. You can find a lot of other such hosting providers. Hope this helps
he just might want to use his own email never used it,but yeah cpanel has an auto responder. why not use an email script?i use one,it is pretty basic.