[exim] exim -> assp

I sent this to the assp list but they didn't seem to know.

I am trying to route outgoing email through assp (a spamfilter proxy)
like this:

MUA --> MTA (EXIM) --> ASSP --> MTA (EXIM) --> internet

The second MTA is on another server.

When I tell exim to do so I get this error. It happens when I send an
email from the address this email came from (I actually did send it to
example@???, assuming that the address can be used for testing,
rfc2606):

2008-01-17 14:15:04 1JFd0q-0004Ij-N1 remote host address is the local
host: example.com
2008-01-17 14:15:04 1JFd0q-0004Ij-N1 == example@??? R=smarthost
defer (-1): remote host address is the local host

assp's logs don't show it ever arrived so I assume assp rejects it for
some reason. It works fine if that instance of exim sends it out itself
or uses another smarthost (also exim).

I figure this isn't the right place to ask but I'll try.
Is there some specific thing I need to configure to allow email
submissions to assp this way? It does work if the MUA directly submits
to assp, but that solution is not ideal (I need encrypted access on port
465 and 587, which exim does fine).

Thanks,
Jeroen