Mailchimp has a free plan. The free plan is the right entry point if you're testing the product before committing.
Free
Free
1 seat included
500 contacts · 1,000 sends/mo · 1 audience · basic templates · branded Mailchimp footer · Marketing CRM lite
Once you hit the free-tier ceiling — usage caps, branding requirements, or feature gates — you'll need to move to a paid tier. See the full Mailchimp pricing.