Socket Exception

[cherry sawant]

Hi,
I am getting an exception - java.net.SocketException: Software caused connection abort:
JVM_recv in socket input stream read
I get this error for the line as follows:
SmtpClient client = new SmtpClient(mailServer);
The constructor takes the ip of the smtp server.
import sun.net.smtp.SmtpClient;
I have never used the sun.net.smtp.SmtpClient before. Where can I find a documentation or Api for knowing it better as I am debugging the code written by someone else.
How do I get the error above?
Thank You..