A man was in his front yard mowing grass when his blonde neighbour came out of the house and went straight to the mailbox.
She opened it, looked inside, slammed it shut, and stormed back into her house.
A little later she came out of his house again, went to the mailbox, again opened it, and slammed it shut again. Angrily, back into the house she went.
As the man was getting ready to edge the lawn, here she came again. She marched to the mailbox, opened it and then slammed it closed harder than ever.
Puzzled by her actions, the man asked her, "Is something wrong?"
To which the blonde replied, "There certainly is! My stupid computer keeps telling me I have mail!"