1. SEARCH_BASE="ou=OURSITE,o=OURORG", $filter="CN=Recipients"
2. SEARCH_BASE="ou=OURSITE,o=OURORG",$filter="cn="
3. SEARCH_BASE="ou=OURSITE,o=OURORG",$filter="cn=*"
4. SEARCH_BASE="cn=Recipients,ou=OURSITE,o=OURORG", $filter = ""
5. SEARCH_BASE="cn=Recipients,ou=OURSITE,o=OURORG", $filter = FILTER_NORMAL_USERS