You can either approve or reject your proofs by logging into "My Account" and clicking the icon (approve proofs) to the right of the project you are working on.
There will be a blank section where you can type in any comments or recommendation for changes that you might want to make.
Click resubmit and the order will be updated with your information.
No need to follow up with an email.
*Note - Editorial changes requested at this point in the production process may incur additional costs and time in production. Please be sure to make all of your edits prior to submitting your order