Thank you for the detailed explanation regarding notification delivery and the analysis of our undelivered notifications. Based on your feedback, it's clear that we have a higher than normal rate of device tokens pointing to devices that are not connected to APNs, which suggests we may indeed have stale tokens in our database. To better address this issue, I have a few questions about token validation: Is there a recommended approach or API call from APNs to proactively validate whether a device token is still associated with an active device before sending notifications? We could call it whenever the app starts. Since we're using AWS SNS as our provider, are there any specific AWS CLI commands or API calls you'd recommend to help us identify and manage stale tokens? What would be considered a best practice for token lifecycle management? For instance, should we be implementing periodic health check notifications to validate tokens, or is there a more efficient method you'd recommend? We'd appreciate any guidance on strategies to maintain a clean and active token database to improve our overall delivery rates. Thank you again for your assistance.