Thanks Ido. With inspiration from your post, I tried the hostname you mentioned. It failed at $yahoo->login or die "Can't login Yahoo!Messenger";
I scanned the registry under Yahoo IM and found the entry for hostname as 'scs.msg.yahoo.com' However, it still fails to login, although it makes Net::YahooMessenger->new connection. Note: Iam able to login with the same userid/password from actual yahoo messenger client.