Which term describes messages that were not successfully delivered due to user actions?

The term that describes messages that were not successfully delivered due to user actions is "bounces." In the context of messaging and marketing, bounces occur when an email or notification cannot be delivered successfully. This can happen for various reasons, such as an incorrect email address, the recipient's mailbox being full, or the user opting out of communications.

Understanding bounces is crucial for marketers as it helps in assessing the effectiveness of their messaging strategies and provides insights into maintaining a clean and engaged contact list. By monitoring bounces, marketers can identify issues with data quality or user engagement, leading to improved targeting and communication tactics over time.

The other terms—unique impressions, deliveries, and push opens—refer to different metrics that do not pertain to undelivered messages. Unique impressions relate to the number of distinct users who see a message, deliveries refer to the total number of messages successfully sent, while push opens indicate how many users opened a push notification on their device. These metrics are essential for analyzing engagement but do not address the specific situation of messages failing to be delivered due to user actions.