[exim] syslog loglevel

hi

i'm sending the log to file and syslog. when logfile is unwriteable the
loglevel for normal messages in syslog is changed from info to critical.
i don't like this.

mail.crit exim[10236]: 2008-06-17 00:31:52 1K8HEY-0008Ub-UG Completed
QT=6h24m46s

my other problem is how could i redirect the delivery error messages to
different loglevel?

thank you for your attention.