Elevated hard bounces for Apple private relay recipients (privaterelay.appleid.com)
Affected: Mailbox Provider Service Interruption
SparkPost Outage History
SparkPost is up right nowSparkPost had 38 outages in the last 2 years totaling 601h 15m of downtime — averaging 1.6 incidents per month.
There were 38 SparkPost outages since December 23, 2024 totaling 601h 15m of downtime. Each is summarised below — incident details, duration, and resolution information.
Outbound message delivery is delayed/slow for some SparkPost customers (EU hosted only)
Affected: SMTP Delivery - EUROPE
Timeline · 3 updates
- investigating Aug 19, 2026, 06:52 PM UTC
We are investigating an increase in delivery latency for some outbound messages. (NOTE: This does not impact our customers hosted in the US.)
- monitoring Aug 19, 2026, 07:44 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Aug 19, 2026, 07:58 PM UTC
This incident has been resolved.
Partial Outage and Delivery Issues in US-West-2 Region
Affected: Transmissions API - USASMTP API - USASMTP Delivery - USA
Timeline · 6 updates
- investigating Jul 24, 2026, 11:14 AM UTC
We are investigating delivery issues caused by an ongoing AWS US West 2 region outage. Customers may experience delays or failures while we assess the impact to our service. We are actively monitoring the situation and will provide updates as more information becomes available.
- identified Jul 24, 2026, 11:53 AM UTC
Outbound email delivery is blocked for our US West region. We working with our vendor resolve the issue. We are continuing to accept emails and queue them internally. We will deliver the messages as soon as the issue is resolved.
- monitoring Jul 24, 2026, 12:08 PM UTC
We are starting to deliver mails in our US West region. We are working through the queued messages. We are continuing to monitor the issue and continuing to accept emails.
- monitoring Jul 24, 2026, 01:16 PM UTC
We are still working through the queued messages. We are continuing to monitor the issue and continuing to accept emails.
- monitoring Jul 24, 2026, 05:29 PM UTC
We have implemented additional tuning to handle the significant influx of mail due to the AWS network outage and we are seeing improvement in delivery rates We are seeing significant recovery and expect most mail to be fully delivered in the next 30-35 minutes. Estimated time for full recovery is 80-90 minutes. We are continuing to look for additional optimizations and monitor the issue.
- resolved Jul 24, 2026, 06:44 PM UTC
This incident has been resolved.
There is a delay effecting some mail sending in EU.
Affected: SMTP Delivery - EUROPESMTP API - EUROPETransmissions API - EUROPE
Timeline · 3 updates
- investigating Jun 29, 2026, 03:58 PM UTC
We are investigating the delay and the impact. We will post once we know more.
- monitoring Jun 29, 2026, 04:05 PM UTC
There was a combination of events that caused a short period of slowdown. That slowdown has already recovered and we are monitoring to ensure we do not see it again.
- resolved Jun 29, 2026, 04:46 PM UTC
This incident has been resolved.
Issue with updating payment information
Timeline · 3 updates
- identified May 12, 2026, 12:48 PM UTC
We’re currently investigating an issue that prevented some customers from updating their payment details. The root cause has been identified, and a fix is being implemented.
- monitoring May 12, 2026, 01:10 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved May 12, 2026, 01:38 PM UTC
This incident has been resolved.
Elevated 5xx Suppression List API error rates and latency for some SparkPost customers (US hosted only)
Affected: Suppression List API - USA
Timeline · 3 updates
- identified May 11, 2026, 06:55 PM UTC
We are experiencing an elevated level of errors and latency on the Suppression List API for some SparkPost customers. Please retry any 5xx error. Note: This issue does not impact SparkPost customers hosted in the EU.
- monitoring May 11, 2026, 07:46 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved May 11, 2026, 08:02 PM UTC
This incident has been resolved.
Delayed delivery for some messages in EU
Affected: SMTP API - EUROPE
Timeline · 4 updates
- investigating May 09, 2026, 09:39 PM UTC
We are looking into why some messages are seeing delayed delivery.
- identified May 09, 2026, 09:50 PM UTC
The issue has been identified and a fix is being implemented.
- monitoring May 09, 2026, 10:05 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved May 09, 2026, 10:17 PM UTC
This incident has been resolved.
Intermittent email injection failures affecting a small subset of customers in Europe
Affected: SMTP API - EUROPE
Timeline · 3 updates
- investigating May 07, 2026, 09:31 AM UTC
We are currently investigating this issue.
- monitoring May 07, 2026, 10:49 AM UTC
A fix has been implemented and we are monitoring the results.
- resolved May 08, 2026, 11:31 AM UTC
This incident has been resolved.
Increased bounce or delay rate for Apple domains
Affected: SMTP Delivery - USASMTP Delivery - EUROPE
Timeline · 4 updates
- investigating Apr 05, 2026, 05:02 PM UTC
We are currently investigating reports of delayed or failed email deliveries to Apple-hosted domains. Messages to non-Apple domains are unaffected. We will provide updates as more information becomes available.
- identified Apr 05, 2026, 05:58 PM UTC
The issue was caused by an Apple iCloud Mail outage (https://www.apple.com/support/systemstatus/), which Apple has since marked as resolved. Bounce rates and delivery delays to Apple domains have returned to normal levels. We are currently reviewing our suppression lists to identify and remove any recipients that may have been incorrectly added during the incident.
- monitoring Apr 05, 2026, 06:27 PM UTC
Apple has implemented a fix and we are monitoring the results.
- resolved Apr 05, 2026, 07:01 PM UTC
Delivery rates to Apple domains have returned to normal with no further elevated delays or bounces. We will perform any necessary post-incident cleanup of suppression lists to ensure no recipients were incorrectly suppressed during the outage. NOTE: As of Monday April 5th at 9PM EDT the cleanup has been completed. All recipient addresses to Apple or Apple Private Relay domains that were suppressed during Apple's incident window were removed.
Email delivery in US region affected
Affected: SMTP Delivery - USA
Timeline · 5 updates
- investigating Mar 12, 2026, 06:51 AM UTC
We are currently investigating issues with delivery of email impacting US region.
- monitoring Mar 12, 2026, 07:48 AM UTC
System is fully recovered and under monitoring.
- investigating Mar 12, 2026, 08:00 AM UTC
Email delivery in US is impacted, experiencing elevated delays.
- monitoring Mar 12, 2026, 10:03 AM UTC
System functionality has been fully restored and all emails are being transmitted correctly without added latencies; we are actively monitoring.
- resolved Mar 12, 2026, 11:25 AM UTC
This incident has been resolved.
Outbound message delivery is delayed/slow for some SparkPost customers (US and EU regions)
Affected: SMTP Delivery - USASMTP Delivery - EUROPE
Timeline · 3 updates
- investigating Mar 05, 2026, 12:51 AM UTC
We are investigating an increase in delivery latency for some outbound messages.
- monitoring Mar 05, 2026, 01:00 AM UTC
We are observing recovery in email delivery performance and are actively monitoring.
- resolved Mar 05, 2026, 01:24 AM UTC
This incident has been resolved.
Microsoft Mail Delivery Delays and Temporary Rejections
Affected: Mailbox Provider Service Interruption
Timeline · 2 updates
- monitoring Feb 26, 2026, 05:55 PM UTC
We are currently seeing elevated temporary rejection rates for email delivered to Outlook.com, Hotmail, and other Microsoft-hosted addresses. Microsoft has acknowledged the issue and is actively investigating. This is a industry-wide issue and not isolated to any specific account. We will continue to monitor and update this page as we receive more information. Next update: When Microsoft posts a resolution or Bird observes delivery rates normalizing
- resolved Feb 27, 2026, 05:38 PM UTC
Microsoft has confirmed that they made additional changes the night of Thursday, Feb 26th that should have remediated most IP rate limiting and rejection issues. If you are still seeing impacts, please reach out via your normal support channels and our team can investigate and escalate with Microsoft.
Elevated 5xx Transmissions API error rates and latency for some SparkPost customers (US hosted only)
Affected: Transmissions API - USA
Timeline · 6 updates
- investigating Feb 24, 2026, 07:07 PM UTC
We are experiencing an elevated level of errors and latency on the Transmissions API (injection API) for some SparkPost customers. Please retry any 5xx error. Note: This issue does not impact SparkPost customers hosted in the EU.
- investigating Feb 24, 2026, 07:07 PM UTC
We are continuing to investigate this issue.
- investigating Feb 24, 2026, 07:25 PM UTC
We are continuing to investigate this issue. We still see 5xx errors on mail injections and degradation.
- identified Feb 24, 2026, 07:34 PM UTC
The team has identified the root cause. There is a core networking issue that has impacted sending across the clusters.
- monitoring Feb 24, 2026, 07:38 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Feb 24, 2026, 07:41 PM UTC
This incident has been resolved.
Outbound message delivery is delayed/slow for some SparkPost customers (US hosted only)
Affected: SMTP Delivery - USA
Timeline · 4 updates
- investigating Feb 24, 2026, 03:01 PM UTC
We are currently investigating this issue. No messages are lost.
- identified Feb 24, 2026, 05:19 PM UTC
The issue has been identified and a fix is being implemented.
- monitoring Feb 24, 2026, 05:34 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Feb 24, 2026, 06:17 PM UTC
This incident has been resolved.
SSO Login Failures Due to reCAPTCHA Configuration Issue
Affected: SparkPost Application - USA
Timeline · 3 updates
- identified Jan 27, 2026, 04:39 PM UTC
We have identified an issue affecting Single Sign-On (SSO) logins. Users authenticating via SSO are unable to access their accounts. A fix has been deployed and we expect the issue to be resolved within the next few minutes. We apologize for the inconvenience and will provide an update shortly.
- monitoring Jan 27, 2026, 04:41 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Feb 05, 2026, 12:22 PM UTC
This incident has been resolved.
Delays in sending emails to Microsoft domains
Affected: SMTP Delivery - USASMTP Delivery - EUROPE
Timeline · 11 updates
Delays in sending emails to yahoo.com domain in EU and US regions
Timeline · 1 update
- resolved Jan 14, 2026, 04:27 PM UTC
We've experienced processing delays of up to 1h30min for sending emails to yahoo.com domain in the EU and US regions.
Delay in event processing.
Affected: Metrics API - USAEvents API - USASparkPost Application - USAEvent Webhooks - USA
Timeline · 3 updates
- investigating Dec 11, 2025, 06:36 PM UTC
There is a delay in our events pipeline. This is causing metrics, events and webhooks to be delayed for a portion of data. Message sending is not effected.
- monitoring Dec 11, 2025, 10:18 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Dec 11, 2025, 10:28 PM UTC
This incident has been resolved.
Longer than expected delays
Affected: SMTP Delivery - USASMTP Delivery - EUROPE
Timeline · 4 updates
- investigating Dec 11, 2025, 04:34 PM UTC
Messages that have failed initial delivery and are in a delayed state are taking longer than expected to resend. Only messages injected via SMTP and in a delayed state are effected.
- identified Dec 11, 2025, 04:57 PM UTC
The issue has been identified and the fix has been deployed.
- monitoring Dec 11, 2025, 05:00 PM UTC
A fix has been implemented and we are monitoring the results.
- resolved Dec 11, 2025, 06:34 PM UTC
This incident has been resolved.
Data processing delays
Affected: Metrics API - USAEvents API - USASparkPost Application - USAEvent Webhooks - USASparkPost Application - EUROPEMetrics API - EUROPEEvents API - EUROPEEvent Webhooks - EUROPE
Timeline · 3 updates
- investigating Dec 10, 2025, 09:22 PM UTC
We are currently looking into a data delay. This is causing our metrics to be delayed. It is not effecting mail sending.
- monitoring Dec 11, 2025, 12:23 AM UTC
Our pipeline that was having issue has recovered. We are monitoring to ensure we stay in a good state. Very sorry for the inconvenience.
- resolved Dec 11, 2025, 12:32 AM UTC
This incident has been resolved.
Increased error rates and latency from our APIs
Affected: Metrics API - USATransmissions API - USAEvents API - USASparkPost Application - USASMTP API - USASending Domains API - USASuppression List API - USABlocklist API - USAAlerts API - USA
Timeline · 3 updates
- investigating Dec 10, 2025, 03:40 AM UTC
We are looking into increased error rates and high latency across our APIs. This could be related to a third party outage.
- monitoring Dec 10, 2025, 04:46 AM UTC
One of our third party providers is experiencing increased latency. This is causing a very small amount of the traffic hitting our APIs to error or have high latency. We are monitoring to ensure the latency and error rates don't increase while waiting for their team to resolve the issue.
- resolved Dec 10, 2025, 06:09 AM UTC
This incident has been resolved.
Data Process is delayed for Sparkpost US - EU
Affected: Metrics API - USAEvents API - USASparkPost Application - USASparkPost Application - EUROPEMetrics API - EUROPEEvents API - EUROPE
Timeline · 5 updates
- investigating Dec 08, 2025, 02:24 AM UTC
Our data processing services are running behind; some customers may see a delay of data available via the: - SparkPost App (webUI): Signals Reports - Events API - Metrics API Message injection and outbound message delivery are not impacted - all messages are flowing as expected.
- identified Dec 08, 2025, 03:21 AM UTC
The issue has been identified and a fix is being implemented.
- identified Dec 08, 2025, 04:26 AM UTC
We have been able to catch up all data from the 5th and are working on the 6th now.
- identified Dec 08, 2025, 04:51 AM UTC
We are continuing to work on a fix for this issue.
- resolved Dec 08, 2025, 05:33 AM UTC
This incident has been resolved.
Data processing delays for SparkPost customers - US and EU regions
Affected: Metrics API - USASparkPost Application - USASparkPost Application - EUROPEMetrics API - EUROPE
Timeline · 4 updates
- investigating Dec 05, 2025, 07:16 PM UTC
Our data processing services are running behind; some customers may see a delay of data available via the: - SparkPost App (webUI): Signals Reports - Events API - Metrics API Message injection and outbound message delivery are not impacted - all messages are flowing as expected.
- identified Dec 05, 2025, 08:24 PM UTC
The issue has been identified and a fix is being implemented.
- identified Dec 05, 2025, 09:43 PM UTC
Metrics API is fully caught up. We are continuing work to restore full data availability in the UI.
- resolved Dec 05, 2025, 10:23 PM UTC
The incident has been resolved.
Yahoo Mail Sending Delays
Affected: Events API - USASparkPost Application - USAEvent Webhooks - USA
Timeline · 4 updates
High response times on the API
Affected: Transmissions API - USA
Timeline · 3 updates
- investigating Nov 27, 2025, 11:24 AM UTC
We are currently investigating this issue.
- investigating Nov 27, 2025, 12:26 PM UTC
We are continuing to investigate this issue.
- resolved Nov 27, 2025, 01:01 PM UTC
This incident was resolved.