Importing content from a URL during message preparation enables you to retrieve the latest HTML content each time the email is prepared. This way, the content of recurring emails is always up-to-date at the time of their sending.
We have improved the retry mechanism for deliveries including content imported from a URL. Read here for more details: Retrieving content from a URL automatically at preparation time
Please feel free to reach out through the below comment section in case you have any questions.
Sukrity Wadhwa