The autoresponse is not working with ISPConfig 3.0.1.4

[voltron81]

Hi to everybody.
I'm almost finish my configuration and I was trying the autoresponder feature.
The system in a Debian with ISPConfig 3.0.1.4.
I create domains and email and it's just working fine.
When I try to setup an autoresponse for one email address, in ISPConfig I write the message and I active the autorespond.
I wait some minutes (cron time) and I try to send an email to that address(from another email of the same domain for example).
From the log I can see that the email is correctly sent, and in fact I'll receive this email to the email address, but the sender doen't receive the autoresponder message.
I checked in /var/vmail/mailfilters/domain/email/ and i have the 2 files .autoresponder and .vacation.msg
The permissions for the whole /mailfilters file and for the .mailfilter file are 600.

There is something that I'm forgotting?
Thanks
Michele