Zendesk requires special configuration actions outside of Authenticate. Please follow these steps to complete configuration for Zendesk, and then return to your automation-guided task list in Authenticate.
1. Make sure you have added Zendesk as an 'Approved Sender' in Authenticate for the domain you are configuring it for.
Note: If Zendesk has not been approved, please do so now by selecting it from the ‘Service Name’ dropdown.
2. The default DKIM keys for Zendesk will be added automatically, but they require activation in the Zendesk platform by your Zendesk administrator.
3. Zendesk requires the publication of a Domain verification TXT record in your DNS after you implement the SPF Record by enabling Zendesk as a Sender. You can see the instructions here.
4. Now log in to your Zendesk account and click Manage -> Email from the Channels category ->
Scroll down to Custom Domain for DKIM and select the Enable option -> Click Save.
You can read more in the article provided by Zendesk.
5. Once you’ve completed these steps, you can begin sending authenticated email using Zendesk.