imap help

[xpressmail]

tell me how to get imap_open() function to work

i tried this , but geting the error message :

Coludnt open stream .......

<?php

$server = "xpressmail.com"; // My own mail server in my machine

$user = "john";

$pass = "mypass";

$conn = @imap_open("{$server/imap}INBOX", $user, $pass)

or die("Connection to server failed");

?>

imap_open() is not working . i am getting error msg couldnot open stream

Is ther any configuration to be done .
i am able see mails using
imap://[e-mail]
i am my mail server now only in local network