In exim-3.16 spec.txt section 47.4 it says:
. A local part prefix such as 'vacation-' can be specified on a director
which causes the message to be delivered directly to the "vacation"
program, or uses Exim's autoreply transport. The contents of a user's
.forward file are then much simpler. For example:
spqr, vacation-spqr
. The require_files generic director option can be used to trigger a
vacation delivery by checking for the existence of a certain file in the
user's home directory. The unseen generic option should also be used, to
ensure that the original delivery also proceeds. In this case, all the
user has to do is to create a file called, say, .vacation, containing a
vacation message.
Does anyone have an example of exim.conf which uses this latter
feature?
