[horde] Certificate failure for mail host.

[Sam]

Hi,

I have just installed Horde with IMP, and run thru the test.php script 
from Mozillar browser, but it failed with teh following error:


  IMP Version

    * IMP: 3.2.4


  PHP Version

    * View phpinfo() screen <http://fbsd/horde/imp/test.php?mode=phpinfo>
    * PHP Version: 4.3.7
    * PHP Major Version: 4.3
    * PHP Minor Version: 7
    * PHP Version Classification: release
    * You are running a supported version of PHP.


  PHP Module Capabilities

    * IMAP Support: *Yes*


  PHP IMAP Support Test

server="slox.xyz.com" user="test at xyz.com" 
mailbox="{slox.xyz.com:143/imap}INBOX"

array(1) {
  [0]=>
  string(202) "Certificate failure for slox.xyz.com: self signed certificate in certificate chain: /C=HK/O=xyz Inc./CN=xyz Inc. CA/emailAddress=mailadmin at xyz.com"
}



My server.php is configured as:
$servers['_prompt'] = array(
    'name' => _("Choose a mail server:")
);

$servers['cyrus'] = array(
    'name' => 'Cyrus IMAP Server',
    'server' => 'slox.xyz.com',
    'protocol' => 'imap/notls',
//    'protocol' => 'imap/ssl/novalidate-cert',
    'port' => 143,
    'folders' => '',
    'namespace' => 'INBOX.',
    'maildomain' => 'xyz.com',
//    'realm' => 'xyz.com',
    'realm' => '',
    'preferred' => ''
);

What other coniguration files I should look at to fix the problem?

thanks
sam