How do I change the user verification source SecurityGateway uses for a domain?

From the Dashboard, after logging in:

1. Click on Setup/Users, in the bottom-left corner.
2. Locate the Accounts section.
3. Click on Domains and Users.
4. Highlight the domain in question.
5. Click on Edit in the top toolbar.
6. Click on the Verification tab.
7. From the Available Sources field, choose the verification source(s) that you wish to use, and click on the right-arrow button to move them into the Selected Sources field.
8. Click on Save and Close to close the domain properties window.