For text messages specifically: the same status-recheck automation used for regular texts also reconciles marketing-campaign texts — if your provider reports a message failed or wasn't delivered, and it hasn't already been refunded, the credit charged for it is automatically returned to your balance. There's no automatic retry of the send itself; the refund is the extent of the automated recovery. Separately, "delivered" and "reply" events for campaign texts are logged in real time so a conditional automation step can react to them right away.