SmartMail's Smart Segments automatically update every 24 hours and whenever an email to the segment is sent. Segments are set to auto-update at 6:00am EST.
If you'd like to manually update your segment before sending a campaign, click the refresh button while on the Smart Segments tab.
or click the Show button within the Smart Segment.
Note: Most segments will update within a minute, but larger lists can take up to 5 mins to populate.