I got the email in September, but no magnet icon in the gfui.
A lot of folks had Snapmarks enabled on a machine that had been returned for repair. Is this your first unit?
Yup, most likely enabled on one of your returned machines. You can verify that by looking in the UI and selecting one of your old machines and see if the magnet is there. I experienced this same thing, and am waiting for it to be enabled on my newest .