[imp] Cannot authenticate local imap

[Mel Sloan]

I have installed horde and imp and not a lot of configuration.  I'm using the horde/imp/test.php.   I cannot log into my localhost:143 imap(same machine) and the error says "cannot establish stream".  I can, however, log into another imap server, where I have an account.  External Outlook express can log into this imap and so can External Netscape mail.   The demo Horde site CANNOT log into my imap either.  

Does this say my imap/pop is incompatible with Horde??

php-4.1.2-7.3.6
php-imap-4.1.2-7.3.6
wu-imap-2001a-15
horde-2.1
imp-3.1