[Exim] Subject: in autoreply (vacation)

Hi All,

I've just configured vacation service using autoreply transport. It looks
like this:


vacation_pipe:
driver = autoreply
file = /home/${local_part}/.vacation
to = ${sender_address}
from = ${original_local_part}@${original_domain}
subject = "Autoreply: Vacation message for ${local_part}@${domain}"
log = /home/${local_part}/.vacation_log
once = /home/${local_part}/.vacation_log_db


and in the DIRECTORS:


on_holiday:
driver = localuser
transport = vacation_pipe
require_files = ${local_part}:/home/${local_part}/.vacation
unseen


Everything works fine.
The only thing I need to do is a user could change its Subject header value.

Now it is always "Autoreply: Vacation message for ${local_part}@${domain}"
but I want to read the content of Subject header from a file, for example
from /home/${local_part}/.subject.

I know that the subject can be read from MySQL database, but I don't want
to involve MySQL.

How to make exim to read Subject value from a file?

Robert