exim4 router problems since 2 days / sucpicous process "zinit" is pstree

[Thorsten Göllner <tg@ovm-group.com>]

Hi,

I have installed Debian 5.0.7. Since 2 days my exim4 does not deliver 
mails. I always get the message, that the mail is not routeable. I only 
used "dpkg-reconfigure exim4-config" without touching one config file by 
hand. I detected a log message (panic log) which says, that there was a 
"too large message". Since that point exim4 stopped working.

The other point is that pstree reports a process "zinit" I never saw in 
the past:
(see last line of output)

# pstree -A
init-+-acpid
     |-apache2---17*[apache2]
     |-atd
     |-cron
     |-exim4
     |-6*[getty]
     |-inetd
     |-mysqld_safe-+-logger
     |             `-mysqld---41*[{mysqld}]
     |-ntpd---ntpd
     |-portmap
     |-python
     |-rpc.statd
     |-rsyslogd---3*[{rsyslogd}]
     |-sensord
     |-smartd
     |-sshd---sshd---sshd---bash---su---bash---pstree
     |-udevd
     `-zinit---{zinit}

I found it here:
# ls -lah /sbin/zinit
-rwxr-x--x 1 root root 1.9M 2008-08-12 16:09 /sbin/zinit

But I do not have any idea what it is. And I can not see the process 
with "ps":

# ps aux | grep zinit
root      5125  0.0  0.0   3120   708 pts/0    R+   12:00   0:00 grep zinit

/* output of exim4 test */
===========================
# exim4 -d -bt tg@ovm-group.com
Exim version 4.69 uid=0 gid=0 pid=4981 D=fbb95cfd
Berkeley DB: Berkeley DB 4.6.21: (September 27, 2007)
Support for: crypteq iconv() IPv6 GnuTLS move_frozen_messages
Lookups: lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmnz dnsdb 
dsearch nis nis0 passwd
Authenticators: cram_md5 plaintext
Routers: accept dnslookup ipliteral manualroute queryprogram redirect
Transports: appendfile/maildir/mailstore autoreply lmtp pipe smtp
Fixed never_users: 0
Size of off_t: 8
changed uid/gid: forcing real = effective
  uid=0 gid=0 pid=4981
  auxiliary group list: <none>
configuration file is /etc/exim4/exim4.conf
log selectors = 00000ffc 00210001
trusted user
admin user
originator: uid=0 gid=0 login=root name=root
sender address = root@nostradamus.urc24.org
Address testing: uid=0 gid=103 euid=0 egid=103
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Testing tg@ovm-group.com
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Considering tg@ovm-group.com
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
routing tg@ovm-group.com
no more routers
tg@ovm-group.com is undeliverable: Unrouteable address
search_tidyup called
>>>>>>>>>>>>>>>> Exim pid=4981 terminating with rc=2 >>>>>>>>>>>>>>>>

Do I have a security issue here? Any other idea?

Thank you in advance,
-Thorsten-