Your segment list in Mailercloud is automatically refreshed once every 24 hours to ensure that it stays up to date with any changes in your contact lists. However, if you need to update the segment immediately or want to see the most recent data, you have the option to manually refresh the list. To do this, simply choose the "Refresh" option located under the "Edit segment" dropdown. This allows you to have the latest and most accurate information for your segments at any time.