SEDNA Outage History

Started Oct 20, 2025, 07:39 AM UTC· resolved Oct 20, 2025, 12:06 PM UTC

1. investigating Oct 20, 2025, 07:39 AM UTC

   Dear Customers, We’re currently experiencing a mail flow issue, which is causing emails to queue and may also impact incoming mail delivery. Our engineering team is actively investigating and working to resolve the issue as quickly as possible. We’ll provide updates as more information becomes available. Thank you for your patience and understanding.

2. identified Oct 20, 2025, 08:11 AM UTC

   Dear Customers, We've identified that the widespread mail flow issue affecting some customers is related to an ongoing AWS outage impacting our infrastructure. As a result, mail delivery and processing may be delayed. Our engineering team is closely monitoring the situation and working with AWS to restore normal service as soon as possible. We’ll share further updates as more information becomes available.

3. identified Oct 20, 2025, 09:14 AM UTC

   Dear Customers, The mail flow issue affecting some customers remains ongoing and is linked to a wider AWS outage impacting multiple services. Our engineers continue to monitor the situation closely and are working to restore full functionality when AWS systems recover. For more information, you can track updates directly from AWS via their status page: https://health.aws.amazon.com/health/status We’ll continue to provide updates as they become available. Thank you for your continued patience and understanding.

4. monitoring Oct 20, 2025, 10:47 AM UTC

   Dear Customers, AWS has confirmed that the underlying issue has been mitigated, and most services are operating normally again. Some throttling and backlogs are still being cleared, particularly affecting the US-EAST-1 region, which may cause intermittent delays or errors. Our team continues to monitor the situation closely and will provide further updates as AWS progresses toward full resolution. Thank you for your patience and understanding.

5. resolved Oct 20, 2025, 12:06 PM UTC

   Dear Customers, We’re pleased to confirm that all services are now operating normally. The earlier disruption, which was linked to an AWS outage in the has been fully resolved. Our systems are stable, and mail flow and processing have returned to normal. We’ll continue to monitor closely to ensure everything remains stable. Thank you for your patience and understanding throughout this incident.

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Started Oct 17, 2025, 07:44 AM UTC· resolved Oct 17, 2025, 12:32 PM UTC

1. investigating Oct 17, 2025, 07:44 AM UTC

   Dear Customers, We’re aware that some customers are currently experiencing issues creating new mail and, in certain cases, receiving mail. Our engineering team is actively investigating and working to resolve the issue as quickly as possible. We’ll continue to provide updates as more information becomes available. Thank you for your patience and understanding.

2. investigating Oct 17, 2025, 08:30 AM UTC

   Dear Customers, Our engineering team continues to investigate the issue affecting customers who are experiencing mail flow issues We’re working to identify the root cause and will share further updates as soon as more information becomes available. Thank you for your continued patience.

3. identified Oct 17, 2025, 09:19 AM UTC

   Dear Customers, We’ve identified the cause of the issue affecting the mail flow. Our engineers are working on a fix and we’ll share another update once it’s resolved. Thank you for your patience.

4. monitoring Oct 17, 2025, 09:44 AM UTC

   Dear Customers, We have identified the root cause of the problem and are actively working on a resolution. We will provide the next update within 15 minutes. Mail sending and receiving may continue to be unavailable – other system capabilities remain unaffected. Thank you for your continued patience

5. monitoring Oct 17, 2025, 09:56 AM UTC

   Dear Customer We have identified the root cause of the problem and are actively working on a resolution. New mail has been successfully flowing into the platform since approximately 10:45AM BST, and older mail is expected to be delivered shortly. We will provide the next update within 15 minutes. Thank you for your continue patience and understanding

6. monitoring Oct 17, 2025, 10:34 AM UTC

   Dear Customers, We're currently processing the queued mail and expect the process to be completed within the next 15 mins. Once this has been completed we will confirm with an update. Thank you once again for your continue patience

7. monitoring Oct 17, 2025, 11:05 AM UTC

   Dear Customers, Our team continues to work on fully resolving the mail delivery issue. While new mail is flowing into the platform, there may still be intermittent issues as we complete the recovery process. We’ve temporarily paused queued mail processing to allow our engineers to address and resolve the root cause. We’re closely monitoring the situation and will provide another update as soon as more information becomes available. Thank you for your continued patience.

8. monitoring Oct 17, 2025, 12:18 PM UTC

   Dear Customers, Mail delivery services have now been restored, and new mail is flowing as expected. The remaining backlog is currently being processed and will be cleared shortly. We continue to monitor performance closely to ensure full stability and update you once everything has been processed. Thank you for your patience

9. resolved Oct 17, 2025, 01:00 PM UTC

   Dear Customers, The backlog of emails has now been fully processed, and mail flow is functioning normally. We understand the inconvenience this may have caused and appreciate your patience as we resolved the issue. The system was first impacted at approximately 8:30AM (GMT+1) with the system partially restored at 10:45AM (GMT+1) and all systems restored and mail delivered at 12:32 PM (GMT+1). We appreciate your patience while we worked to resolve the issue, we will be delivered a full incident report by end of day on Monday October 20.

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Started Aug 29, 2025, 01:36 PM UTC· resolved Aug 29, 2025, 04:13 PM UTC

1. investigating Aug 29, 2025, 01:36 PM UTC

   As per Microsoft: ID: EX1144276 Issue type: Incident Status: Service Degradation Impacted services: Exchange Online Details: Title: Users may experience delays sending and receiving email messages User impact: Users may experience delays sending and receiving email messages. Current status: We're reviewing service monitoring telemetry to isolate the source of the issue and establish a fix. Scope of impact: Some users who are located in Europe attempting to send or receive Exchange Online email messages may be impacted. Next update by: Friday, August 29, 2025, at 2:30 PM UTC

2. investigating Aug 29, 2025, 01:38 PM UTC

   Aug 29, 2025, 4:38 PM GMT+2 The new throttling rule has successfully been deployed. We’ve received confirmation from some of the previously affected users that they can now send and receive email. Additionally, our telemetry shows that the new throttling rule is having the desired effect and providing relief. Next update by: Friday, August 29, 2025 at 6:00 PM GMT+2

3. investigating Aug 29, 2025, 04:12 PM UTC

   Aug 29, 2025, 5:38 PM GMT+2 After monitoring the service and receiving confirmation from previously affected users, we’ve confirmed that impact has been remediated. The service will now resume periodic attempts to deliver emails that were sent during the impacted period. Issue details Issue ID: EX1144276 Affected services: Exchange Online Status: Service restored Start time: Aug 29, 2025, 12:36 PM GMT+2 End time: Aug 29, 2025, 5:10 PM GMT+2 Issue type: Incident

4. resolved Aug 29, 2025, 04:13 PM UTC

   This incident has now been resolved

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Started May 15, 2025, 08:10 AM UTC· resolved May 16, 2025, 09:30 PM UTC

1. investigating May 15, 2025, 08:54 AM UTC

   We are currently investigating an issue impacting automatic mail forwarding in Exchange Online: Issue ID EX1072592. Affected users may experience delays or failures in receiving forwarded mail due to a fault within the Exchange system. Our Engineering team is actively investigating and closely monitoring the situation. We will provide further updates as more information becomes available

2. monitoring May 16, 2025, 09:26 AM UTC

   Microsoft Exchange Online has completed the deployment of a code fix to address the underlying regression, which has resolved the issue for newly sent messages. They are now initiating a targeted recovery process for messages affected during the impacted timeframe and are actively working on a scalable solution to ensure full remediation: Issue ID EX1072592 As a result, some previously unforwarded emails may now begin to be delivered. Sedna customers may notice the arrival of older messages - potentially up to a few days old - as part of this recovery effort. We will continue to monitor the situation and provide updates as new information becomes available

3. resolved May 20, 2025, 10:29 AM UTC

   Final Update on Exchange Online Forwarding Issue — Issue ID: EX1072592 Microsoft has confirmed that messages users attempted to forward between 2:04 PM UTC on May 11, 2025, and 5:00 AM UTC on May 16, 2025, will not be automatically replayed. Sedna users who wish to have emails from this period re-forwarded should contact Microsoft Support directly and reference Issue ID EX1072592. This will allow Microsoft to initiate a manual recovery of the affected messages.

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Started Apr 23, 2025, 11:58 AM UTC· resolved Apr 23, 2025, 12:13 PM UTC

1. investigating Apr 23, 2025, 11:58 AM UTC

   An application outage has been identified and is affecting customers on Dublin 1 infrastructure. Affected users are unable to log into or access the platform. The issue is under investigation by engineering as an emergency.

2. identified Apr 23, 2025, 12:06 PM UTC

   The issue has been identified and a fix is being implemented.

3. monitoring Apr 23, 2025, 12:13 PM UTC

   A fix has been implemented and we are monitoring the results.

4. resolved Apr 23, 2025, 12:18 PM UTC

   This incident has been resolved.

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Started Apr 18, 2025, 07:40 AM UTC· resolved Apr 18, 2025, 09:20 AM UTC

1. investigating Apr 18, 2025, 09:03 AM UTC

   We are currently investigating this issue.

2. monitoring Apr 18, 2025, 09:05 AM UTC

   A fix has been implemented and we are monitoring the results.

3. resolved Apr 18, 2025, 09:27 AM UTC

   This incident has been resolved and our Engineers are continuing to monitor the situation.

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Started Mar 03, 2025, 05:22 PM UTC· resolved Mar 03, 2025, 06:26 PM UTC

1. investigating Mar 03, 2025, 05:35 PM UTC

   An application outage has been identified and is affecting all customers on Dublin 3. Affected users are unable to log into or access the platform. The issue is under investigation by engineering as an emergency.

2. resolved Mar 03, 2025, 06:38 PM UTC

   This incident has been resolved.

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Started Mar 03, 2025, 01:34 PM UTC· resolved Mar 03, 2025, 06:38 PM UTC

1. investigating Mar 03, 2025, 01:42 PM UTC

   Customers on our Dublin 3 cluster are experiencing a temporary delay in receiving mail. The issue is under investigation by engineering as an emergency.

2. monitoring Mar 03, 2025, 01:53 PM UTC

   A fix has been implemented, and mail ingest has been resolved. We are currently monitoring the delayed auto-tagging of the affected messages.

3. resolved Mar 03, 2025, 06:38 PM UTC

   This incident has been resolved.

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Started Feb 24, 2025, 12:30 AM UTC· resolved Feb 24, 2025, 12:40 PM UTC

1. resolved Feb 24, 2025, 01:12 PM UTC

   All customers may have experienced a temporary delay in receiving mail between 12:15pm to 12:40pm UTC. The issue has now been fully resolved. We sincerely apologize for any inconvenience and appreciate your patience.

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Started Oct 28, 2024, 08:08 AM UTC· resolved Oct 28, 2024, 08:47 AM UTC

1. identified Oct 28, 2024, 08:08 AM UTC

   The issue has been identified and a fix is being implemented.

2. resolved Oct 28, 2024, 09:51 AM UTC

   This incident has been resolved.

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