After addressing a widespread outage that affected Outlook.com users worldwide on Monday, Microsoft has asked iPhone users to re-enter their credentials to regain access to their Outlook and Hotmail accounts via the default Mail app.

Microsoft confirmed the incident yesterday morning, saying that customers were experiencing intermittent sign-in issues that prevented them from accessing their mailboxes via Outlook.com.

In a later update, it added that some of the affected users were also being signed out of their accounts and seeing "too many requests' errors.

Before mitigating the outage, roughly 10 hours after the first user reports, Microsoft blamed the Outlook.com sign-in issues on a "recently introduced change" but didn't share any further details.

On Monday evening, around 7 PM UTC, the company said the service health had returned to normal, but added that iOS users "must" manually re-enter their credentials to access their accounts via the default Mail app by going through the following step-by-step procedure:

1. Open the Settings app on your iPhone.
2. Scroll down and tap on Mail.
3. Select Accounts under the Mail settings.
4. Tap on the email account for which you need to re-enter the password.
5. Tap Account Settings or the Password field directly (depending on your iOS version).
6. Enter the updated or correct password in the Password field.
7. Tap Done to save the changes.
8. Open the Mail app to confirm that the account is syncing properly and emails are being sent/received.

Microsoft hasn't shared more information about the outage's root cause and hasn't disclosed which regions or how many users were affected.

However, the incident was flagged as causing "service degradation," a label typically used for incidents with noticeable user impact that don't take the service offline for everyone.

In March, Microsoft also addressed an Exchange Online outage that blocked customers' access to mailboxes and calendars via Outlook on the web, Outlook desktop, Exchange ActiveSync, and other Exchange Online connection protocols.

The same day, it resolved a separate issue that caused Microsoft 365 Copilot and Office.com sign‑in problems impacting the Microsoft Copilot desktop app, Copilot in Microsoft Teams, and Copilot in Office apps.

More recently, in early April, it resolved a known issue that prevented some Classic Outlook users from sending or replying to emails via Outlook.com, and they were instead receiving non-delivery reports (NDRs) with 0x80070005-0x0004dc-0x000524 errors.

Microsoft is also investigating an issue that causes the mouse pointer to disappear for some users in Classic Outlook, OneNote, and other Microsoft 365 apps, as well as a bug that triggers "Can't connect to the server" errors when creating groups in Classic Outlook.

99% of What Mythos Found Is Still Unpatched.

AI chained four zero-days into one exploit that bypassed both renderer and OS sandboxes. A wave of new exploits is coming.

At the Autonomous Validation Summit (May 12 & 14), see how autonomous, context-rich validation finds what's exploitable, proves controls hold, and closes the remediation loop.

Claim Your Spot