Vanguard voice biometric enrollment: the wrong way to do security

This showed up in my email. What’s wrong with it?

It tells me to click on a link to get started. How do I know this is really a Vanguard email? 

For something involving account security at this level it should give me instructions on how to proceed after I’ve logged in to my Vanguard account.

I believe this is a legitimate email, but I can’t trust it.