Exim recently started failing and this was the only error in 'exim_paniclog' that showed up but not always. Sometimes it fails without any error whatsoever.2006-09-18 19:17:05 non-existent configuration file(s): /etc/exim.conf
The way it fails is curious because it stops listening on the standard SMTP port but keeps the secure, encrypted port open.
I wasn't able to track the cause and thought if anyone else had a similliar problem.