Email subject Line  Number of Sent  Number of Open
A MasterCard For You!   113 8
Act now to line up for your request immediately 5011    470
Action requested to proceed further with your application   6427    544
Advance Request Notification    1123    94
User action pending notification    1540    934

Email$SubjectLine <- as.character(Email$SubjectLine)
All.words <- strsplit(Email$SubjectLine, c(" "))
words <- unlist(All.words)
word.count <- table(words)
chosen.words <- names(word.count)[word.count>3]