I am using an 1.6.2 OPENLDAP edition of iRedMail running on Ubuntu 20.04.5.

I am able to login and send mail to myself using my Active Directory Credentials using secure ldaps on port 636.

I am trying to tie the global address book into Roundcube and have followed the article on the website.  I have enabled logging in Roundcube and this is the error I am getting:

16:16:07 mail roundcube: <ojb1tkel> LDAP Error: Could not connect to any LDAP server in /opt/www/roundcubemail-1.5.3/program/lib/Roundcube/rcube_ldap.php on line 494 (GET /mail/?_task=mail&_action=list-contacts&_source=global_ldap_abook&_page=1&_remote=1&_unlock=loading1667924167709&_=1667924163562)

My config file /opt/www/roundcubemail/config/config.inc.php has the following parameters in it (I have edited out my domain name, OU and credentials):

// Global LDAP address book.
$config['ldap_public']["global_ldap_abook"] = array(
    'name'              => 'Global LDAP Address Book',
    'hosts'             => 'domain.com',
    'port'              => 636,
    'use_tls'           => true,
    'ldap_version'      => '3',
    'network_timeout'   => 10,
    'user_specific'     => true,

    // Search mail users under same domain.
    'base_dn'       => 'ou=myou,dc=domain,dc=com',
    'bind_dn'       => 'user1',
    'bind_pw'       => 'password',
    'hidden'        => false,
    'searchonly'    => false,
    'writable'      => false,

    'search_fields' => array('mail', 'cn', 'sn', 'givenName', 'street', 'telephoneNumber', 'mobile', 'stree', 'postalCode'),

    // mapping of contact fields to directory attributes
    'fieldmap' => array(
        'name'          => 'cn',
        'surname'       => 'sn',
        'firstname'     => 'givenName',
        'title'         => 'title',
        'email'         => 'mail:*',
        'phone:work'    => 'telephoneNumber',
        'phone:mobile'  => 'mobile',
        'phone:workfax' => 'facsimileTelephoneNumber',
        'street'        => 'street',
                                                                                                                     93,44         70%