Add an option to disable spam filter, or total remove it.
It does no good.
Today most important mails are taken by the spam filter, but almost no spam is taken. It seems that Yahoo has swapped it around. When I mark no spam, it continues to send the sender to spam folder, even the idea with no spam was it should not, and add it to a whitelist, guess.
Also, it seems like any spam has found a way around the spam folder.
Jens Madsen shared this idea