Email piping is optional for Autoresponder PRO functionality. But you can use Email subscriptions feature if you have email piping feature in your hosting panel. Host panels like Cpanel, Hsphere, Plesk, Directadmin - all comes with Email piping unless your host deliberately disables it on some panels.

Email piping means redirecting email that are coming to an email address to a php/cgi script.

This can be done using .forward, .qmail-default, .procmailrc or any file based on your host configuration.

To attain this you should remember two things - 1. POP3 account should NOT be there for that email address from which you piping email to autoresponder script. Because POP3 catches the email before it will redirected to autoresponder script. 2. You need to set up other POP3 accounts for your regular correspondence like webmaster@yourdomain.com or you@yourdomain.com etc., so these regular email won't be redirected to autoresponder.

Ask your host this question: 'Can I redirect(pipe) email from my catch-all email account to a php script?'