Auto-Responder on Catch All Address

[pfmartin]

How do you get a catch all address to send auto-response? For example:

[email protected]

I setup an autoresponder for this.

If an email comes to [email protected], it is forward to the catch all but no auto-response is generated. However, if I email [email protected] directly I do get the auto-reponse. Any idea why?

Thanks