Email is an indispensable tool for communication and users might have to deal with large volumes of information which they can not always operate efficiently. For these users, the organization of emails is a tedious task. The use of automatic filters is not always possible or effective, because of difficulties regarding how to create a specific rule or because their use is impractical in some situations. In this article, we present an approach to enhance a webmail client with an interface agent that helps the user to label incoming email based on the knowledge of the user´s preferences. We not only considered the label that can be applied to different emails but also how to better interact with the user to provide him/her with assistance in the labeling procedure. We performed a set of experiments using Google´s webmail system, Gmail, obtaining a good rate of acceptance of the agent interactions.