[exim] How to configure Exim3 for SMTP-time message reject.

Hi all,

I'm new to the list, and I find nothing about that on the archives. So
I'm asking to you.

I want to reject mails directly at SMTP-time when localpart is
wrong. My config contain the following directors:

- Amavis
- Spamassassin
- Mailman
- Virtual Domains
- User forward
- Localuser

All mails are accepted by Amavis/Spamassassin, then rejected with a
DSN if wrongs. The problem is that I receive a lot of messages where
To: field is a Message-Id. (eg: 87u1dlhlf9.fsf@???)

I want to be able to reject messages before Amavis/Spamassassin cycle,
but I don't know how.

Any idea or link accepted.