We have developed SummaryBIFF, a new e-mail delivery system for mobile phones that sends a summary of each newly arrived message and the URL connected to the HTML file converted from the message. The summary is generated by our sentence extraction method that takes the features of e-mail messages for business use into consideration. Our method uses the features as cue phrases and modalities that play important roles in business messages. A user can read not only the summary of a message but also the whole message directly through the URL over the user’s mobile phone if necessary.