appending {HEAD ~ e mail identification data} into a header of the mail thread of {TAIL ~ the at least two e mail messages} when transmitted, wherein the e mail identification data includes at least: 
appending { HEAD ~ e mail identification data } into a header of the mail thread of { TAIL ~ the at least two e mail messages } when transmitted , wherein the e mail identification data includes at least :
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH