Your current spam filtering is ineffective (i.e., completely worthless). You should instead allow us to set filters that (1) take precedence over yahoo spam filtering (or enable us to filter spam without having you redirect it first to 'bulk mail'), (2) immediately delete things we flag as spam, that is, without delivering it to trash, bulk mail, spam or anything else (I don't need to see stuff I know is spam), (3) you should allow us to set a spam filter that automatically deletes an email where ANY header or any other formatting characteristic we define (for example, anything having any email address, to, cc, reply, from, mail-from, etc. that begins with "reply@, news*, etc." and (4) even better, allow us to set complex rules outside of headers (e.g., reject email having HELO that matches 'value y', or having a specific dmarc, d value or other type of value we want to kill). Right now, yahoo (a) delivers notorious spam through trivial evasion of yahoo filters, but seems to flag legitimate emails as spam and not deliver them and (b) doesn't allow us to set effective filters that would at least delete the spam yahoo seems incapable of deleting. You need a more effective solution, i.e., right now I'd characterize you as "industry worst."