Quoted from Leocg
**It is disabled or it is enabled? If it's disable, your spam filter will not work and the job will be done by the server's spam filter only.
Also, if you have "learn from labeled messages" enabled, the filter will take a while to learn what to mark as spam.**
Thanks Leocg... my spam filter is on, set to strong filter, but because of the default view setting,
all the spams continued to be present in my inbox... thanks to the explanation by Burnout426 I can
make most of the spam disappear from view
So, apparently the spam filter doesn't delete the unwanted messages, but you can make them invisible 🙂