Head over to https://privacy.circleci.com, and click on the Make a Privacy Request button (in green).

Select the Do not contact option in the modal as seen below.

Enter your email address to receive a confirmation message and verify your identity.

You will then receive an email to log into the Privacy Center.

Confirm your request in the Privacy Center.

It should be noted that notifications for your builds are not covered by this opt out process. You will receive build notification emails for any project that you are following in CircleCI. If you would like to stop receiving notifications for builds, please follow the steps found in this article:

How Do I Stop Getting Build Notification Emails For Projects?