Help - Zumbi

[maschimidt]

Hello everyone
I'm having a serious problem
I just delete a queue Messanges 13380
I have some infected machine on my network in which my antivirus can not detect the mail soon

BD5401191495 5180 Thu May 12 07:38:03 report#####. com.br (delivery temporarily suspended: connect to vesta-hw.stech.net.br [200.152.245.124]: 25: No route to host) 200909170423.n8h4noje004323 @ @ vesta vesta-hw.stech.net.br 200909170423.n8h4noqa004329 hw.stech.net.br-20090

Account informe@#####. com.br there on my server, and the log shows only Received: from localhost (localhost [127.0.0.1]) by mail .######. com.br (Postfix) with ESMTP id 9E1C01193862; Thu, 12 May 2011 07:37:39 -0300 (EDT)
It consists not identify the machine on my network that is sending these emails, because it shows the IP of the machine, only localhost
In the web console in the Queue email in the source IP 127.0.0.1 it also shows
Can anyone help me, is this change?

My version of Zimbra is: zimbra-mta-6.0.6_GA_2324.RHEL5

Thanks..