If we change email for activation registered account too quiqly then
enqueue_activation_email method of
users_controller enqueue job without delay, so we got message to old email. May be it should be something that:
Jobs.enqueue_in(2.second, :critical_user_email, type: :signup, user_id: @user.id, email_token: @email_token.token)
or may be it possible to set low priority to that job?