how to connect the other machine user to our localhost in xmpp while using ejabbered server

Hi Sir,
I am using ejabbered server in my localhost and i have created accounts in localhost through pidgin interface and the protocol is XMPP.
Similarly i have created another account in other machine using ejabbered server through pidgin interface and the protocol is XMPP.
But the instant chating is working for the accounts created within the localhost.
It is not working for the accounts in my machine and the accounts in the another machine.
The message delivered to the user in other machine is failed eventhough that user was in online.The buddy list cannot able to authorize the user in other machine.
How to connect the user in other machine.