Substack experienced a major incident on October 20, 2025 affecting Email delivery, lasting 11h 11m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Oct 20, 2025, 01:41 PM UTC
We are experiencing delays with processing scheduled posts related to an outage from one of our service providers. Our team is investigating.
- investigating Oct 20, 2025, 01:49 PM UTC
We are also seeing issues with publication dashboards including partial outages across the subscriber tab and some statistics. We are working to mitigate.
- identified Oct 20, 2025, 02:12 PM UTC
We are seeing recovery of our publisher dashboard functionality. Other service functions such as scheduled posts continue to be degraded.
- identified Oct 20, 2025, 04:51 PM UTC
We continue to experience delays with processing scheduled posts related to an outage from one of our service providers. Users can publish posts manually to bypass this. Our team is still investigating.
- monitoring Oct 20, 2025, 09:50 PM UTC
Scheduled post sends are operational and we have caught up with the backlog.
- resolved Oct 21, 2025, 12:52 AM UTC
This incident has been resolved.