[Exim] archiving outgoing mail on remote host

Hi,

I was wondering if there is a clever trick to archive outgoing mails
(ie routed by routers) on a remote host without a new message being
generated, something à la smarthost driver for directors).
This will probably be possible in Exim 4, but if someone could
direct my to some trick on Exim 3, that would be really great.
I'm currently using Exim 3.20 on SUN/Solaris 8.

What I have now is a domainlist router with a condition set to
check the sending addresses to archive.

auto_archiver_out:
driver = domainlist
# this is to avoid that incoming mails which are being automatically archived
# via my-to-archive-address@my-archive-host are re-archived here.
domains = !my-archive-host
route_list = * HD2ARC_HOST bydns_a
condition = ${lookup{${lc:$sender_address_local_part}}lsearch{EXIM_TABLES/HD2ARC-users}{yes}fail}
transport = auto_archiver_out
unseen

And the transport a rather straightforward pipe transport.

auto_archiver_out:
driver = pipe
return_output
log_output
log_defer_output
command = /usr/bin/mail HD2ARC_ADDR
group = EXIM_GID
user = EXIM_UID

On the other side, I can then catch HD2ARC_ADDR easily.
BUT, a new message is generated in the process.

Now there IS a good reason to keep the archive an a remote host,
so moving the archive to the localhost is a big no-no.

Well it's being a long day at the desk and maybe I don't see
the obvious right now. A good night's sleep might shed some
light on this :-))

Any idea is welcome!

Thanks in advance.

Bernard Stern, SWITCH