Email spoofing is a very big trouble for the internet users since long. Emails with forged headers, where the senders name are altered to make it seem like it came from some other source is called a spoof email. The activity is thus called email spoofing. This can cause a great deal of trouble to anyone because it might make the email receiver to actually believe that the email came from the original source. So if the one sending the spoof email has some basic details about the person he is sending the email to, he can use filthy tricks to make a lot out of it.