This Yahoo PayDirect email which states that someone has sent you money is a hoax and part of a phishing scam ...

Using the link in this very convincing email will open some similarly convincing but forged Yahoo PayDirect pages in your browser. To add to the complexity of the ruse, the perpetrators have coded the initial web page to reopen the forged content in such a manner to exploit the URL Spoofing vulnerability which exists in unpatched Internet Explorer browsers. This means that an apparently genuine URL will be displayed while the page is actually located elsewhere (see above report summary).

If you have received this email, please remember that it is very common for these email scams to be redistributed at a later date with only slightly different content or the same but with the fake page(s) hosted by a different provider. Also, once you have received one of these hoaxes, it is also common place to receive at least another one and usually a day or two after the first, although not necessarily from the same apparent sender.

The Spoof Email ...