If you configured your check-in to be public, and selected a team as a recipient, any submissions will be added to a team page and included in the team daily digest email.
You can turn off digests from your Notifications settings page:
From here, you'll be able to change the digest time, or disable digests completely:
For private check-ins, or public check-ins with individual recipients, each recipient will receive an email as soon as it's submitted. You can similarly turn this off on the notification settings page: