I cnt acess yahoo mail to my mobile whn i try to connect my mail through gprs answer comes refused by servr?

i cnt acess yahoo mail to my mobile whn i try to connect my mail through gprs answer comes refused by server.enter your mail server.same problem comes in my yahoo im service.curently am using nokia 5800 xpress music with the idea gprs connection.pls help me and pls provide me yahoo mail and im server with full details means incoming and outgoing server name for mail.and server detail for im services.my ph num is 09889492814.pls hlp me out thnks.