The default settings for LDAP Recipient Verification are:

LDAP Server: IP Address or FQDN of your LDAP Server (Use LDAPS:// in front of this address to use LDAPS)
LDAP Port: Default port is 389
LDAP Anonymous Search: This will be set to no for Exchange/Active directory servers.
LDAP Search User DN: Username that SpamTitan will use to connect to your LDAP server, use email address format i.e. user@domain.local
LDAP Password: Password for LDAP Search User
LDAP Query Filter: (|(proxyaddresses=smtp$%s)(proxyaddresses=smtp:%s)(mail=%s))
LDAP Result Attribute: mail

LDAP Search Base: Based off your domain name. If internal domain was domain.local then the search base would be DC=domain, DC=local