An apparatus and method for classifying e-mails using a decision tree is
disclosed. The apparatus includes: a client e-mail storing unit for
storing e-mails according to each folder; a decision tree generating unit
for generating a decision tree based on information about e-mails stored
according to folders in the client e-mail storing unit; a received e-mail
processing unit for receiving e-mails; an e-mail storing unit for storing
the e-mails received in the receiving e-mail processing unit; an e-mail
classifying unit for classifying the e-mails stored in the e-mail storing
unit based on the decision tree; an e-mail transmitting unit for
transmitting the classified e-mail to the client e-mail storing unit; and
a controlling unit for controlling the units to generate the decision
tree based on the e-mails stored in the client e-mail storing unit and to
classify the e-mail transmitted from outside based on the decision tree.