Answer
This is a scam. yahoo do not operate a lottery or give away any monetary prizes. check out this website for confirmation of this yahoo scam and how to report this scam to yahoo.
http://www.consumerfraudreporting.org/lotteryscam_yahoo2.php
unscrupulous thieves have sent you this email and they are trying to part you from your hard earned cash. they will often ask you to call a premium rate number and keep you holding on whilst you rack up a huge phone bill. they are then paid a large proportion of this phone bill. they may ask you to divulge personal information about yourself or ask for your bank or credit card details. do not divulge any such information under any circumstances. it is
surprising how man
y innocent victims have been duped by these types of emails.
remember the thieves who send them are
clever and
convincing. i suggest you delete the email and send it into cyberspace, hopefully along with the thieving scumbags who send them.
check out these sites for further information :
http://www.scambusters.com
http://www.hoax-slayer.com/