Using pine?

1. Type M(ain Menu), then S(etup), then R(ules), then F(ilters), then Enter.
2. Page down one screen and use the arrows to select Add Extra Headers. Hit Enter.
3. Type in X-Spam-Flag. Hit Enter twice and type in YES.
4. Page down (roughly four screens) to Filter Action and select Folder List.
5. Type in the name you wish to use for your spam folder (for example, spam).
6. Type E(xit), saving changes when prompted, and E(xit) again.