Choose manual refresh to send using the last complete contact copy saved on your PC. Use Refresh contacts from source when you need newer data. A new list must complete its first full refresh before sending.
With automatic refresh, the app updates contacts when a new send actually starts, including a scheduled send. If that update fails, the new send does not start using an older contact copy. This is not continuous background synchronization.
Continue and Retry Failed retain the original run’s saved audience and personalization data. Automatic mode rechecks the eligibility of those saved recipients; it does not add newly discovered people. The run retains the refresh policy with which it started. Scheduled sending still requires the app to be running and the PC awake and connected. See the MySQL contact-list guide.
