If it's spam, how do you know what they're selling? You absolutely should NEVER open mail when it's clear it's spam/scam/junk mail. The spam folder gets emptied for us by Yahoo every 3 days or so, so there isn't even a need to delete. You can generally tell by the unfamiliar address, and the subject line. If it's in your In Box, you still don't open it... just either mark it as spam or delete it. You don't even EVER need to open the Spam/Bulk mail folder unless you were expecting something in your InBox that you hadn't received. Some people will actually respond to junk mail, but doing so just confirms that you have interest and causes them to send more. But there's no way to stop it, but to mark it as spam. But in all honesty, many of these people have programs that keep generating new address so many are almost impossible to even block.
