I received exactly the same email with a different sender ("Anna Roland", a resident of San Francisco, California) and was also left quite paranoid by it. The email had an combative tone and felt like a legal threat.
You can avoid snaps by using Synaptic Package Manager. I learned this the hard way after installing Xubuntu 20.04 and finding every piece of software I installed from Ubuntu Software Center was either a slow, buggy or completely broken snap image.
I really dislike the way snaps create disk partitions. When I run $ df I want to see what I defined during OS installation, not a dozen nasty snap mounts. An application misusing fundamental system features like this feels like a violation of some UNIX principle.