I need to report an email Scam letter to Yahoo Admin?

I keep getting a bogus UK letter informing me of Lotto prize winnings. Today I get a similar one but this one has "Microsoft" attached to the Sender's Title. I've been Deleting and Spamming all these past Mails. It's all become more than a pain in the tushy. I would like for You to give me the Link where I can rapidly report these People!! Thank You so much.