Hi Thom,
Thanks for reaching out! While this functionality isn’t available as a built-in component of our plugins at this time, you may find the third-party plugin Event Calendar Newsletter to be an acceptable solution for this issue! If you’re interested in learning more, you can read about this plugin and its capabilities on their documentation here:
https://eventcalendarnewsletter.com/docs/subscriptions-tec-mailchimp/
Please note that this plugin is not developed by us, and we are not affiliated with its creators in any way–that said, it’s a solution that’s well-liked by a number of our users, so we’re happy to share it in case it might be useful! 🙂
I hope that helps! Thanks again, and let us know if you should have any other questions!