IPN Verification via Java code times out over HTTPS

[Rambot]

I have been trying to test the IPN verification response by POSTing back my IPN request back to the PayPal sandbox (Using Apache HTTPClient). But it times out:04/06/2013 12:22:29 PM HTTP JVM: java.net.ConnectException: Connection timed out04/06/2013 12:22:29 PM HTTP JVM: at java.net.PlainSocketImpl.socketConnect(Native Method)04/06/2013 12:22:29 PM HTTP JVM: at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:383)04/06/2013 12:22:29 PM HTTP JVM: at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:245)04/06/2013 12:22:29 PM HTTP JVM: at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:232)04/06/2013 12:22:29 PM HTTP JVM: at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:377)04/06/2013 12:22:29 PM HTTP JVM: at java.net.Socket.connect(Socket.java:539)04/06/2013 12:22:29 PM HTTP JVM: at com.ibm.jsse2.tc.connect(tc.java:77)04/06/2013 12:22:29 PM HTTP JVM: at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:549)04/06/2013 12:22:29 PM HTTP JVM: at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:180)Here is the call I am using just to test the connection: HttpPost httppost = new HttpPost("http://www.sandbox.paypal.com/cgi-bin/webscr?cmd=_notify-validate");Do we need to provide login credentials to post back?