In the Connections page in Census, click the Add Service button under the Service Connections section, and select Mailchimp.
You will be redirected to a page to log in to Mailchimp to authorize your account to Census. Once you enter your credentials and click the Log In button, you'll see a page like the image below, confirming you want to authorize Census.
Once you've authorized Census, you'll be redirected back to the Connections page in Census and you should see your Mailchimp connection there.
If you want to see your connections in Mailchimp in the future, simply navigate to the Profile page, and scroll down to the Connections and notifications section.
💡⠀Mailchimp Field Quirks
Please note that the mandatory status field only accepts the following values in lower case: "subscribed", "unsubscribed", "cleaned", or "pending".
With Mailchimp, the API endpoint needs a Status field value, so if you find yourself seeing this error:
But you don't want to overwrite existing Statuses in Mailchimp, you just need to provide a mapping to the field labelled, "Status For New Subscriber".
Then your test sync, or completed syncs will be good to go, like this one:
If you do want to update the Status field, you can include that instead. However, we highly recommend understanding your organization's implications of potentially re-subscribing a member that has previously unsubscribed.
To prehash your emails, first lowercase the email address and then apply an MD5 hash, both which can be done directly in SQL. For example, here's the SQL you'd use in Snowflake (syntax for other data warehouses vary slightly)