Hello, Kindly have a look at this custom-developed application 

https://apps.odoo.com/apps/modules/17.0/ewall_mailchimp

Hope this helps! 

Hi,

If you were searching for a contacts sync between Mailchimp and Odoo, it is possible to do so with PieSync. You can sync contacts 2-way and in real time, meaning that any new contacts and/or updates to existing contacts will be synced. Here's more information about the integration: http://www.piesync.com/odoo/mailchimp/

Hope this helps,

Grega