I do NOT want the Yahoo system to divert possibly valid emails to its Spam mail folder. There are too many cases of emails being incorrectly marked as Spam when they are genuine. I do not routinely look at the webmail; emails should ALL be transferred to my email client (Outlook) so that I can decide which emails I want to read, which I can ignore and delete. If there is any Spam diversion, it should be within Outlook.
I have set filters so that all emails with "@" in the To or CC fields are sent to my Yohoo Inbox, and now if they contain my name.
Why doesn't Yahoo Mail respect my wishes?
It used to be possible to send all mail to the client (Outlook) to deal with, but unfortunately it is no longer possible to configure webmail in this fashion. BTYahoo think they know better than the customer!!! It is an absolute pain to have to keep checking webmail for false positives.
You could, of course, configure Outlook as IMAP rather than POP3 and sync the Spam folder.