[exim] Getting to email text file during data ACL?

Exim 4.52 with spamd and demime support
compiled in.

Goal: Run a program and pass the path of the
current message.

Attempted to get to the file with this syntax
(found on the web):

set acl_m0 = ${run {/usr/bin/crm /etc/crm/mailfilter \
</var/spool/exim/scan/${message_id}/${message_id}.eml \
--stats_only --fileprefix=/etc/crm/ } {$value} {$value}}

The program (crm mailfilter) is RUNNING but likely not
receiving the data and therefore always returning a
0.0000 result (this should be a positive or negative
number in this format.)

Questions:

1) Is /var/spool/exim/scan/${message_id}/${message_id}.eml
the path to the current message file during Data ACL
processing?

2) Is the full email file available then? Some other way?
    

3) Is the name I am using correct for current versions of
    Exim, i.e., 4.52?

4) Ideas for this?


--
Herb Martin