I have had this same issue, but now I have the following showing on my dashboard:
Mailchimp for Woocommerce
We dectected that this site has the following constants defined, likely at wp-config.php file: MAILCHIMP_DISABLE_QUEUE
These constants are deprecated since Mailchimp for Woocommerce version 2.3. Please refer to the plugin official wiki for further details.
What is the new constant to stop so many requests to the server?
Thank you.