CCBChimp is an approved 3rd party app to sync CCB to Mailchimp.
We get CCB to sync (or talk) to Mailchimp. This is a 2-way dialogue (or connection). So, Mailchimp is where you send your emails. All CCBChimp does is integrate both applications.
If you already have CCB and Mailchimp, all you need to do is add CCBChimp. Our plans start at $10/m, but we recommend the $20/m plan -- the added syncing options will make your integration more effective. https://ccbchimp.com/#pricing
Getting just a CCBChimp account does not include the cost of Mailchimp—adding Mailchimp will be an additional cost.
Mailchimp free plan
Mailchimp has changed the terms of its free plan. Now, you can have up to and including 500 contacts. You can send up to and including 1000 emails per month, with a daily limit of 500 emails. Here is what Mailchimp says about the Free plan on their website:
This may not be what you need.
Check Mailchimp's other plans
You can use the Mailchimp estimator to see which plan you need: https://mailchimp.com/pricing/free-details/
The good news is that they offer a 15% discount for non-profits.