Yeah, well, harry, it's not great to get yet another pitifully brief reply from you. I don't know about other contributors, but my patience is wearing thin. Your responses are too brief to provide any clear indication of whether you now have some understanding of the various points about email clients, POP mail vs. webmail, etc., that have been discussed here, or whether you're still clueless about this stuff.
Look, you've been given ample information in this discussion to draw a conclusion. What would that conclusion be?
1) Yahoo sucks for spam control.
2) If you want to resolve the spam issue, you need to move away from Yahoo and move to another email service, one that will give you some serious spam control options.