dividing the mail thread into {HEAD ~ respective segments} by analyzing {TAIL ~ the at least two thread body intervals} of the thread body field in the each of the related e mail messages 
dividing the mail thread into { HEAD ~ respective segments } by analyzing { TAIL ~ the at least two thread body intervals } of the thread body field in the each of the related e mail messages
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH