[Exim] invert queue_only_file?

I have this thing in my exim.conf:

queue_only_file = smtp/var/run/offline

and it works alright. But I think there should be a way to invert this,
so it can just check for /var/run/pppd0.pid instead. Is there some way
to do that?

--
Björn Lindström <bkhl@???>
http://bkhl.elektrubadur.se/