spam in my email

recently i have received lots of unwanted mails in my yahoo in box, too numerous to count.

they are from different people, different organisation, different sender.
some claims to be from irish or british national lottery or mexican national lottery, but the message is the same, a winning notification that my email address has won a million poundsterling or dollar in their sweepstakes draw that was drawn from emails address worldwide.
all of those emails came in single week. it is quite a nuisance, how come these people has bothered me with this kind of emails. surely i would not believe this kind of stuff.
a million pounds knocking at my doorsteps????
life is not easy like that ha ha ha ha :D
can you believe it if I won a million pounds ten times in just a week?
but it is quite bothering me sometime, a million pound in my bank???.
while some others claiming to be vip refugee in certain african country needs help to get their money from their bank account in europe and promise a huge sum of money,
the other forms are from numerous people claims to be the boss or the chief executive from african development bank situated somewhere in african countries,
offering me a million dollars worth of a dormant account that i can claim right away.
these really getting to my nerve. just a waste,
that what i call a junk mail in the truest sense.
my advice is never to reveal your email address to open/public site in the web,
there might be people watching for more email addresses for them to add to their mailing list,
unless you want to received thrash like i do. Some say these people has  a search engine that check emails address for them to collect. 
so watch out your inbox