[Exim] startup trouble

Hallo again all

I have successfully installed exim but now I am trying to start it up.
It keeps coplaining about the logfile that it cannot open yet I have given it
the correct permissions.
if I do "su "mailman" -c 'touch /var/log/exim/hallo'"
The file hallo is created so my permissions sre correct

darkstar:~ # /usr/exim/bin/exim -d -q15m
Exim version 4.12 uid=0 gid=0 pid=30462 D=fddcaefd
Berkeley DB: Sleepycat Software: Berkeley DB 4.0.14: (September 9, 2002)
Support for:
Authenticators:
Routers: accept dnslookup ipliteral manualroute queryprogram redirect
Transports: appendfile autoreply pipe smtp
changed uid/gid: forcing real = effective
uid=0 gid=0 pid=30462
auxiliary group list: <none>
configuration file is /etc/exim
log selector = 0106ccd8
trusted user
admin user
originator: uid=0 gid=0 login=root name=root
30462 changed uid/gid: running as a daemon
30462 uid=502 gid=100 pid=30462
30462 auxiliary group list: <none>
30462 LOG: MAIN
30462 exim 4.12 daemon started: pid=30462, -q15m, not listening for SMTP
30462 LOG: PANIC DIE
30462 Cannot open main log file "/var/log/exim_mainlog": Permission
denied:uid=502 egid=100
30462 2003-03-13 13:21:32 Cannot open main log file "/var/log/exim_mainlog":
Permission denied: euid=502 egid=100
30462 exim: could not open panic log - aborting: original error above
30462 search_tidyup called
30462 >>>>>>>>>>>>>>>> Exim pid=30462 terminating with rc=1 >>>>>>>>>>>>>