Changes to Get email delivery info

the response property capacity/boost_expires_at became nullable for the status 200

added the new undefined enum value to the capacity/boost_expires_at response property for the response status 200

added the optional property capacity/boost_expires_at to the response with the 200 status

added the required property capacity/boost_multiplier to the response with the 200 status

added the required property capacity/is_boost_active to the response with the 200 status