[exim] acl_smtp_mail help

hi all,
I'm trying to use acl_smtp_mail (exim4 on ubuntu)

The acl does not work, like it wasn't there.

For example my config.autogenerated is as follow, bat every mail is
accepted:

acl_smtp_mail:

deny message = User has been blocked
         senders  = *

deny

What I'm missing ?

thanks