I am writing a PHP script to connect to an Exchange server and read messages from a mailbox. I have it connecting to my inbox just fine. What I'm trying to do now is get PHP to connect to a different mailbox that I have access to (Let's call it "Test Mailbox").

I tried this code:

```
imap_open( '{mail.domain.com:143}Test Mailbox', 'myusername', 'mypassword' );

```

But it said the mailbox doesn't exist. How can I get a list of mailboxes or get the path to the mailbox?