Can I password-protect my suggestion page?

Yes! If you want to make sure only authorized people can submit suggestions, simply click on Edit from the Options menu button for that box, go to the Settings tab and toggle the box under Password from OFF to ENABLED, and enter a password. You'll need to remember to distribute the password along with the box URL to anyone who is submitting suggestions.

This also password-protects your public reply page, if you have that enabled.

Suggestion Ox boxes are not included in search engine indexes.

You can also restrict submissions to specific domains using the Direct Replies feature.