{TAIL ~ Incoming message packets} are intercepted and screened for {HEAD ~ readily discoverable characteristics} indicative of an infected message 
{ TAIL ~ Incoming message packets } are intercepted and screened for { HEAD ~ readily discoverable characteristics } indicative of an infected message
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH