I've hit a snag with SPF. The SPF record for my domain will contain four or five entries, plus it will contain: include:sgizmo.com

The SPF record for sgizmo.com contains eleven entries! This, plus mine, is way over the maximum ten allowed by the RFC (and probably by most servers). I realize that there has to be a limit in order to prevent DoS attacks. However, in the real world, it is probably not unreasonable for large companies to have many server addresses.

Furthermore, must I know monitor my 'include:' counterparts for changes and additions? Must I check weekly, daily, to insure that some combination of changes doesn't suddenly put me over the top? It doesn't seem to me that SPF is suitable for prime time.

Is there another way to do this?