We take messages about exceeds the maximum size of packet like this:
25341:20130730:012646.659 Message size 137312463 exceeds the maximum size 134217728 bytes. Message ignored.
25341:20130730:012646.659 Error while receiving answer from server 
There is not possible to understand what host is generated so much information. Would be great add host related information to message, like this:
25341:20130730:012646.659 Zabbix took a message from [Proxy name/agent name/unknown sender] with [IP]. The message size 137312463 exceeds the maximum size 134217728 bytes. Message ignored.