I keep getting loads of spam emails, how do i block the sender from sending any more of them to me?

Trying to block Spam is a colossal waste of time (and not recommended by mail programs)----because It's ineffective. Spammers change their addresses---(just by one letter or dot)---with "each" batch they send out and never reuse an old one, so they slip easily past any blocks you can make. By the time Spam mail gets to your inbox (or the spam folder) they have already abandoned that address and moved on to a new address. AND---Blocking an abandoned address is useless. Just click the Spam tag on them, and let Yahoo deal with them---which they do by sending them to the Spam folder (instead of the inbox) and deleting them at preset times. Each user is ultimately responsible for the amount of spam they get, by the way they use their account. If you really want to get rid of Spam---YOU have to co-operate with the Spam Guard by -----NOT opening any spam mail (which just generates more of the same)----AND not EVER clicking the unsubscribe link. Hit the Spam tab OR delete them. Unfortunately, it's "nearly" impossible--(once you open their Spam mail and verify your address as "valid and responsive"), to totally eliminate it. You have to be vigilant in protecting your address from them. Check out "Mailwasher", it's a "big" help in eliminating spam from your inbox... Click this link, for information about it. It allows you to bounce emails back to the sender---saying address not found. They won't waste their time sending, (or sharing your address with their cronies)---if they think they have an invalid address---So---Spammers will soon stop sending anything to you. That's the theory anyway, and it seems to work pretty good. Note: the program is free but limited to one email account. http://www.mailwasher.net/