- Level
- confirmed
- Worst impact
- Degraded
- Components
- Mailbox Provider Service Interruption
- Down Index
- 22of 100
What to do
Check whether you use SparkPost Mailbox Provider Service Interruption. Check your stack
Paste a package.json, lockfile, Terraform or a list of domains at down.guide/stack to see every provider you depend on.Confirm your retries, queues and scheduled jobs caught up after the 4h 54m it lasted.
Anything that failed between 2026-08-27 18:03 UTC and 2026-08-27 22:56 UTC may need a replay.Subscribe to SparkPost's feed to hear about the next one first. RSS feed
https://down.guide/feed?provider=sparkpost works in Slack (/feed subscribe), Discord feed bots and any RSS reader.
Updates from SparkPost 5
- identified
Beginning 2026-08-26 around 23:00 UTC, we are observing a significant increase in hard bounces for messages sent to recipients at privaterelay.appleid.com, the relay domain used by Sign in with Apple. Affected messages are rejected by Apple's mail servers with the SMTP response 550 5.1.1 user not found. Our investigation confirms this originates upstream at the receiving mailbox provider, not within our platform. Delivery to all other domains, including icloud.com, me.com, and mac.com, remain unaffected and are performing normally. A substantial share of the affected addresses delivered successfully as recently as 2026-08-26, indicating the rejections do not reflect genuine invalid recipients. Impact: Because these are hard bounces, affected recipient addresses may be automatically added to your suppression list, which will prevent future sends to those recipients even after the underlying issue is resolved. Action required: None at this time. We recommend you do not attempt to manually clean or re-import affected suppression entries while the issue is ongoing. We are working directly with Apple on a resolution. Once resolved, we will remove suppression entries created by this event and will confirm the scope and timing in a follow-up update. We will post our next update within 4 hours or sooner if the situation changes.
provider
- identified
We continue to see elevated 550 5.1.1 user not found hard bounces from Apple private relay. Once resolved on the provider's side, we will automatically remove Apple Private Relay suppression entries created by this event.
provider
- identified
We have started to see recovery of the Apple private relay domain. We will continue monitoring for the next 60 minutes to confirm full recovery. Our team is actively working on automatically removing any suppressions that were created by this event. We anticipate the cleanup to be completed between 4-6PM EDT.
provider
- monitoring
We have seen recovery of the Apple private relay domain to pre-event bounce levels. Our team is actively working on automatically removing any suppressions that were created by this event. We anticipate the cleanup to be completed by 6PM EDT.
provider
- resolved
The Apple bounce levels have maintained at pre incident levels during our monitoring phase. Our clean up of the bad suppressions has finished. This incident is resolved.
provider
Reports count in aggregate; nothing about you is shown.
Corrections
None so far.
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Questions about DWN-01194383f4
Is SparkPost still down?
No, this incident was resolved 2026-08-27 22:56 UTC. For SparkPost's live state, see https://down.guide/sparkpost.
How long did it last?
4h 54m, from 2026-08-27 18:03 UTC to 2026-08-27 22:56 UTC, by the times SparkPost posted.
What was affected?
SparkPost named Mailbox Provider Service Interruption.
What caused it?
SparkPost hasn't published a root cause. If it does, it shows here.
Where does this come from?
SparkPost's official status page, https://status.sparkpost.com, quoted verbatim. down.guide's own probes, reports and social counts are labeled as ours.