How to require email verification only on some accounts (ie admin signup requires email verification, a general user does not)

I have a site that currently only allows content admins to register and they are required to verify their email address so we have ' implements MustVerifyEmail' on the user model and this works well. However we are now allowing the general public to register as well and we don't want these users to get the email verification email, or need to verify their email at all.

How do I make the email verification only required for some user roles & not others? They register through a different form that goes to different controller actions so is there something I can put in the controller action to disable the email verification email being sent for regular users?