Whenever a notification email is sent to your customers, the FROM address that is used can be customized in your Shopify admin.
NOTE: OrderlyEmails does not send any emails itself. Shopify continues to send all of your notification emails, but now with the better email designs created in our app.
Navigate to the Shopify admin -> Settings -> Store details page by clicking this link:
In the Contact Information section, find the "Sender email" field, and change the email address to the one you would like your Shopify notification emails sent from.
Click the "Save" button, and you are done! Now Shopify will use that email address when sending emails to your customers.