Step 1. Login to AiTrillion, head to the customers' panel, and click on add a filter.

Step 2. In the filter selection panel, find the filter for birthday under 'Customer' and select the same.

Step 3. Select the 'is empty' option and then apply the filter to create your segment of customers who do not have a birthday entered.

Step 4. Save your segment and give it a name.

Step 5. Now head over to Email Marketing > Workflow Automation>WorkFlows>Create

Step 6. Create a workflow as shown below by dragging and dropping a trigger, a filter, and an action.

Step 7. Make your settings, choose your throttling options, click save and turn on your workflow.