i test with this to found the error.
echo '"user":"Squid proxy-caching web server"' | /usr/lib/squid/ldap_auth -v 3 -D "uid=zimbra,cn=admins,cn=zimbra" -w PASSWORD -b "ou=people,dc=server,dc=com,dc=uy" -f "(&(objectClass=zimbraAccount)(uid=%s))" -h serverIP
add this line to squid.conf
auth_param basic program /usr/lib/squid/ldap_auth -v 3 -D "uid=zimbra,cn=admins,cn=zimbra" -w PASSWORD -b "ou=people,dc=server,dc=com,dc=uy" -f "(&(objectClass=zimbraAccount)(uid=%s))" -h serverIP
enjoy. |