To answer your question about where Mixpanel updates are added if the website or server is down, I can provide you with the following information based on the knowledge sources:
Mixpanel provides a system status page where you can subscribe to updates and be alerted about any downtimes. The URL for this page is:
Mixpanel Status
You can subscribe to Mixpanel system status updates on this page to receive alerts about any service interruptions or downtimes.
This information comes from the Mixpanel documentation on Beyond Onboarding, which suggests subscribing to Mixpanel system status updates to stay informed about any potential issues with the service.