Notification Service — Digest and Summary Email Delivery Delays In US and Europe Regions

Update timeline

1. resolved Aug 05, 2026, 11:59 AM UTC

   From 24 July at 19:00 UTC, customers in the US and EU region experienced issues receiving Digest and Summary emails from the UiPath Notification Service. The issue has now been resolved, and email delivery has been restored. We are continuing to monitor the service to ensure stable delivery.

2. postmortem Aug 13, 2026, 11:13 AM UTC

   ## Customer impact Between July 24, 2026 19:00 UTC and August 6, 2026 23:00 UTC, customers in the US region did not receive Digest and Summary emails from the UiPath Notification Service. Customers in the Europe region were similarly affected between July 30, 2026 12:00 UTC and August 5, 2026 11:59 UTC. These emails deliver scheduled digests of product notifications on each customer's configured cadence. No other regions or Notification Service functionality were affected. No notifications were lost: all notifications remained available in the in-app notification center throughout the incident, and the emails accumulated during the impact window were delivered after the fix. No customer action was or is required. ## Root cause The background jobs that assemble Digest and Summary emails were processed through a single, serialized execution lane in each region, with limited parallelism inside each run. When one customer's unusually large volume of notifications entered the pipeline, processing it occupied that lane for extended periods and repeatedly timed out — blocking scheduled email runs for all customers in the region. The differing onset dates (July 24 in the US, July 30 in Europe) reflect when each region's load crossed this threshold. ## Detection The issue was reported through a customer support ticket. No automated alert covered digest email delivery volume, which is why the failure went undetected for this period; closing this monitoring gap is the primary preventive follow-up from this incident. ## Response After the issue was acknowledged on August 5, 2026, we confirmed that Digest and Summary emails were not being delivered in the US region and, upon checking all regions, Europe was also affected. All other regions were verified healthy. A fix was deployed on August 5, 2026 to the US region by 07:45 UTC and to the Europe region by 09:45 UTC, and email delivery was verified in both, though delays remained while the large accumulated backlog drained. The fix removed the serialization so scheduled email runs execute independently, and follow-up improvements increased processing parallelism and throughput to accelerate backlog delivery. The accumulated emails from the impact window were then delivered: most schedules caught up within hours, and daily digest delivery completed over the following day. The incident was resolved on August 5 at 11:59 UTC, and we continued monitoring delivery and confirmed resolution with affected customers. ## Follow up 1. **Detection (deployed)** — We are adding automated alerting on digest email delivery volume in every region, so that any interruption in delivery is detected within minutes rather than through customer reports. 2. **Recurrence prevention (deployed)** — The serialization defect was corrected, processing parallelism was made tunable per region, and the affected schedule now runs with a tightened execution timeout and automatic retry so a single long or failing run cannot stall subsequent runs. 3. **Architectural remediation (in progress)** — We are re-architecting the batch email pipeline to separate email scheduling from email delivery to avoid noisy-neighbor issues, and to add per-schedule health visibility.