So I found the wiki page,

I am not an LDAP guy, so forgive my ignorance. How might I be able to have it search all domains (if I have multiple domains stored on the box)

As opposed to doing:

AuthType Basic
AuthName DDInternal
AuthLDAPURL ldap://yourzimbraserver/dc=yourdomain,dc=com
require valid-user
if I had like 10 domains to look through, what could I do to have it search all ten as opposed to the single domain above?