Once you've created a new workflow, you'll add an "Email health and fatigue automation" step to your workflow.  The email health and frequency automation is designed to automatically suppress the right number of people for you to reach optimal email health. To do this, you need to enter your average open rate from the last 30 days. To find this number, view the HubSpot Email Health dashboard.  Select your average open rate from the menu, and press "Save" as shown below:

Once you've created a new workflow, you'll add an "Email health and fatigue automation" step to your workflow.

(Beta) Email health and fatigue automation

Underneath the Email health and fatigue action step, you'll want to add a "Value equals" branch action to create and display the branches. The property that you want to branch on is the "Email health and fatigue automation" and then select "Delivery action", check the box to create the branches, click next and then save.

1. (Beta) Email health and fatigue automation

Underneath the "None met" branch, this is where you'll add a delivery time optimization action and the send email action to complete the build of the template.

Unless you want to perform a different action for contacts that are being suppressed from the mailing, you should not put anything underneath the "Suppressed contacts" branch.

The branch underneath the "None met" will look as follows.

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Contact enrollment trigger
Choose the triggers that decide how a contact enters this workflow.
Set up triggers
1.(Beta) Email health and fatigue automation
Actions
After this step, add a "Value equals" branch below to display and create branches for contacts that should be suppressed from this mailing. Anyone who should recieve the mailing will flow down the "None met" branch.
2.Value equals branch
Actions
Branch on the value "Delivery action" from "1.(Beta) Email health and fatigue automation"
Suppressed Contacts
None met
3.Email delivery time optimization
Actions
Add a "Send email" workflow action step below which will deliver the email to each contact at their optimal time within the selected delivery window.
4.Send email
Actions
Tutorial Email - 1

Increasing Your Sending Domain's Health and Reducing Email Subscriber Fatigue in HubSpot