To send automated emails to Contacts in HubSpot based on delivery status, you can use a workflow. Instructions:
Start by going to HubSpot > Workflows > Create workflow > From scratch > Contact-based and choose Blank workflow.
From the workflow, add a trigger, and choose to trigger the workflow When filter criteria are met.
When you get to the filter, begin typing "Sendoso" into the search bar. You will see "Sendoso" as a category under Integrations.
Select it, and then select "Sendoso: Gift Event Sync Status Properties".
You can now filter by Sent Status and then trigger email actions.
Now you will be able to create a workflow (with multiple branches if needed) that automatically emails Contacts based on their Sendoso delivery status. See the example below.