The last column of 'spambase.txt' denotes whether the e-mail was 
considered spam (1) or not (0), i.e. unsolicited commercial e-mail.  
Most of the attributes indicate whether a particular word or
character was frequently occurring in the e-mail.  The run-length
attributes (55-57) measure the length of sequences of consecutive 
capital letters.  For the statistical measures of each attribute, 
see the end of this file.  Here are the definitions of the attributes:

48 continuous real [0,100] attributes of type word_freq_WORD 
= percentage of words in the e-mail that match WORD,
i.e. 100 * (number of times the WORD appears in the e-mail) / 
total number of words in e-mail.  A "word" in this case is any 
string of alphanumeric characters bounded by non-alphanumeric 
characters or end-of-string.

6 continuous real [0,100] attributes of type char_freq_CHAR
= percentage of characters in the e-mail that match CHAR,
i.e. 100 * (number of CHAR occurences) / total characters in e-mail

1 continuous real [1,...] attribute of type capital_run_length_average
= average length of uninterrupted sequences of capital letters

1 continuous integer [1,...] attribute of type capital_run_length_longest
= length of longest uninterrupted sequence of capital letters

1 continuous integer [1,...] attribute of type capital_run_length_total
= sum of length of uninterrupted sequences of capital letters
= total number of capital letters in the e-mail

1 nominal {0,1} class attribute of type spam
= denotes whether the e-mail was considered spam (1) or not (0), 
i.e. unsolicited commercial e-mail.