Sometimes you may want to upload a large list of email addresses and then have the system drip them out over a certain period, hence the name “drip surveys”.
You can use the email batches for this purpose as well.
For instance, say you have a customer list of 180,000 email addresses. And you want them sent out over a three month period. Then you would calculate how many per hour that is. 180,000 / 90 days = 2,000 per day. 2,000 / 24 hours = 83 per hour. So then you would set your batches to 83 emails every 60 minutes.