[exim] autoreply once on multiple systems

Hello everybody,
is there an easy solution to share the autoreply "once" data between
multiple hosts? The documenation mentions a file or a DBM database in
which these can be stored. I'd like to set up multiple Exim hosts in
order to spread the load with an identical configuration and don't want
host B to also autoreply when host A has already sent the autoreply.

Kai