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