Users may experience issues accessing Outlook.com.

Update timeline

1. monitoring Apr 27, 2026, 10:15 AM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. Current status: We’re analysing service telemetry and investigating reported behaviour to determine scope and next steps. Next update by: Monday, April 27, 2026, at 11:30 AM UTC

2. monitoring Apr 27, 2026, 11:26 AM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Some users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Current status: Our investigation indicates client sign-in scenarios may be contributing to the reported behaviour, and we're focused on validating interactions across service components to identify next steps. Next update by: Monday, April 27, 2026, at 12:30 PM UTC

3. monitoring Apr 27, 2026, 12:23 PM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Current status: We’re reviewing a recent change as part of our ongoing investigation and determining next steps. Next update by: Monday, April 27, 2026, at 1:30 PM UTC

4. monitoring Apr 27, 2026, 01:17 PM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Current status: We're reverting a recently introduced change to determine if this action provides relief from impact upon completion. In parallel, we're continuing to analyze customer reports, and we're closely monitoring service telemetry to identify our next steps and potential mitigation actions. Next update by: Monday, April 27, 2026, at 2:30 PM UTC

5. monitoring Apr 27, 2026, 02:22 PM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Additionally, impacted users may include, but are not limited to, iOS users. Current status: We've completed reverting the recently introduced change, however, this has not produced any relief. We're continuing to investigate the unexpected increase in error rates affecting two separate error scenarios to identify any potential root cause which may be responsible for this. Additionally, we're closely monitoring service telemetry to discover any other potential actions, or mitigation steps. Next update by: Monday, April 27, 2026, at 3:30 PM UTC

6. monitoring Apr 27, 2026, 03:29 PM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Additionally, impacted users may include, but are not limited to, iOS users. Current status: We’re seeing specific errors related to authentication key failures. We’re working to determine the underlying cause in order to determine our next mitigation steps. Next update by: Monday, April 27, 2026, at 4:30 PM UTC

7. monitoring Apr 27, 2026, 04:18 PM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Additionally, impacted users may include, but are not limited to, iOS users. Current status: We're running tests to reproduce impact in our internal environment to obtain additional logging to isolate the source of the unexpected error messages. Next update by: Monday, April 27, 2026, at 5:30 PM UTC

8. monitoring Apr 27, 2026, 05:25 PM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Additionally, impacted users may include, but are not limited to, iOS users. Current status: We've identified a recent service change that is potentially contributing to user impact. We're testing a roll back of this change to determine if this remediates impact. In parallel, we're continuing to investigate the unusual error patterns that were previously observed. Next update by: Monday, April 27, 2026, at 6:30 PM UTC

9. monitoring Apr 27, 2026, 06:30 PM UTC

   User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Additionally, impacted users may include, but are not limited to, iOS users. Current status: The roll back that was completed does not appear to have provided the intended impact relief. We're continuing to look at internal reproductions of the impact to find potential next steps for mitigation and understand the source of error messages. Next update by: Monday, April 27, 2026, at 7:30 PM UTC

10. monitoring Apr 27, 2026, 07:25 PM UTC

    User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Additionally, impacted users may include, but are not limited to, iOS users. Current status: After reviewing the logs collected from internal reproductions we've found a pattern of errors that point to a recent backend configuration change that may be causing impact. We've completed a roll back of this configuration change. We're now carefully monitoring the environment to determine if it worked as intended or if there are additional steps required for full incident resolution. Next update by: Monday, April 27, 2026, at 8:30 PM UTC

11. monitoring Apr 27, 2026, 07:51 PM UTC

    User impact: Users may experience intermittent issues signing in to Outlook.com. More info: Users may experience intermittent sign‑in failures, including “too many requests” errors or unexpected sign‑outs. Impacted users may include, but are not limited to, iOS users. iOS users on iPhones may need to take the following steps to re-enter their password and access their accounts: -Open the Settings app on your iPhone. -Scroll down and tap on Mail. -Select Accounts under the Mail settings. -Tap on the email account for which you need to reenter the password. -Tap on Account Settings or directly on the Password field (depending on your iOS version). -Enter the updated or correct password in the Password field. -Tap Done to save the changes. -Open the Mail app to confirm that the account is syncing properly and emails are being sent/received. Current status: The roll back of the previously mentioned configuration change is complete and our telemetry indicates service health is recovering. We'll continue to monitor to confirm this fully resolves the issue. iOS users may need to take additional steps to re-enter their password to successfully access Outlook accounts. Please see the steps in the "more info" section above. Next update by: Monday, April 27, 2026, at 9:00 PM UTC

12. monitoring Apr 27, 2026, 08:58 PM UTC

    User impact: Users may experience intermittent issues signing in to Outlook.com. More info: iOS users on iPhones MUST take the following steps to re-enter their password and access their accounts: -Open the Settings app on your iPhone. -Scroll down and tap on Mail. -Select Accounts under the Mail settings. -Tap on the email account for which you need to reenter the password. -Tap on Account Settings or directly on the Password field (depending on your iOS version). -Enter the updated or correct password in the Password field. -Tap Done to save the changes. -Open the Mail app to confirm that the account is syncing properly and emails are being sent/received. Current status: While the service remains healthy, we're keeping this notification so users can take the actions outlined in this communication: iOS users MUST take additional steps to re-enter their password to successfully access Outlook accounts. Please see the steps in the "more info" section above. Start time: Monday, April 27, 2026, at 8:45 AM UTC End time: Monday, April 27, 2026, at 7:16 PM UTC Next update by: Monday, April 27, 2026, at 10:00 PM UTC