[exim] How to do this?

Hi,
This is my first question to the list.
Im looking for a solution to a simple problem.
I have a domain ( for example garcia.org), and in this domain i have a
lot of user, but i have one special user notify@???
This user, send email to other user's at every domain (even to users in
garcia.org).
I need that every email send by notify@??? can get a Delivery
report if the mail was read.
The problem is that this funcionality isnt support by all clients
(MUA's/MTA's).
For solve this, i need send for every message, a new email that anounce
the posibilty of get a original message if you reply a message (like a
subscription to a Mailing lists), and if the message is reply then send
the original message and make a log entry with the date of delivery, ip
and other relevant data.
I try to do this using a system filter but i get some errors.
At end the system is like a reverseTDMA system or comercial systems like
"productive mail" or others.
I dont look for a system 100% safety, i look a system capable to get a
Delievery report of every message with the "best effort" (as good as the
smtp protocol can)

The first "strike" to built a System filter:

# Exim filter
if error_message then finish endif
logfile /var/spool/exim4/store/_LOGFILE
logwrite "TO: ${local_part:$recipients} FROM:
${local_part:$sender_address}"
testprint "${if exists{/var/spool/exim4/store/${local_part:$recipients}}
{yes} {no}}"
testprint "${local_part:$recipients}"
if "${if
exists{/var/spool/exim4/store/${local_part:$recipients}}{yes}{no}}" is
"yes"
then
logwrite " ... relevant data ..."
# i need do something to send the message store at
var/spool/exim4/store/${local_part:$recipients} to the originator of
current email
fail
finish
elif "${local_part:$sender_address}" is "notify"
then
headers add "X-agarcia-org: ${hmac{md5}{mysecret}{$message_id}}
$message_id "
save /var/spool/exim4/store/${hmac{md5}{mysecret}{$message_id}}
logwrite "$tod_log $message_id ${hmac{md5}{mysecret}{$message_id}}
$recipients $sender_address $return_path $message_size"
mail to $recipients
from ${hmac{md5}{mysecret}{$message_id}}@???
subject "Tienes un mensaje ${hmac{md5}{mysecret}{$message_id}} "
finish
# logwrite "NO Existe ${local_part:$recipients}"
endif
# logwrite "${if
exists{/var/spool/exim4/store/${local_part:$recipients}}{yes}{no}}"



Some idea about this?

Thanks a lot, and excuse my english.


Alberto Garcia
Spain.