Is the user account validated? Send an email to their email string. Is it not validated? Then why are we even at a point in the code where we're considering emailing the user, except to validate the email.
You can use similar logic to what you described, but instead with something like User and ValidatedUser. I just don't think there's much benefit to doing it with specifically the email field and turning email into an object. Because in those examples you can have a User whose email property is a ParseError and you still end up having to check "is the email property result for this user type Email or type ParseError?" and it's very similar to just checking a validation bool except it's hiding what's actually going on.