Gnus / ifile doesn't learn ;

Hi;

I receive mails that I wish I could read and keep that are sent to the
spam folder everytime, even if also every time I change them to a
non-spam folder.

What could I do (in .idata ?) to ensure a mail from a specific person
doesn't go to the spam folder.

I also have the same problem in the other way. Spam I continu to receive
from the same entity that doesn't go to the spam folder.

Pascal