The naive Bayes (NB) model has been successfully used to tackle spam, and is very accurate. However, there is still room for improvement. We use a train on or near error (TONE) method in online NB to enhance the performance of NB and reduce the number of training emails. We conducted an experiment to determine the performance of the improved algorithm by plotting (1-ROCA)% curves. The results show that the proposed method improves the performance of original NB.