The Connector for Microsoft Outlook can be configured to bind using a DN and password or to bind as anonymous. To enable anonymous access to the corporate directory, add an ACL at the root level of the ou=people/ou=group sub-trees.
For example, if the root level is dc=red,dc=sesta,dc=com, do the following:
#ldapmodify -D "cn=Directory manager" dn: dc=red,dc=sesta,dc=com changetype: modify add: aci aci: (targetattr != "userPassword") (version 3.0;acl "Anonymous access"; allow (read,compare,search) (userdn = "ldap:///anyone");)