21. The system of claim 20 , wherein processing the message further comprises removing one of a quotation or a signature block from the message.
20. The system of claim 19 , wherein selecting the exactly one of the first sentence or the second sentence comprises: computing a first score for the first sentence, the first score equaling the third number divided by the first number; computing a second score for the second sentence, the second score equaling the fourth number divided by the second number; when the first score is higher than the second score, selecting the first sentence as the summary text; and when the second score is higher than the first score, selecting the second sentence as the summary text.