All articles tagged with #exchange online
Microsoft says it will block legacy TLS 1.0/1.1 for POP and IMAP in Exchange Online starting July 2026, requiring TLS 1.2 or newer. Most users are unaffected since modern clients already use TLS 1.2+, but legacy devices or apps may stop connecting and must be updated. Customers should verify their POP/IMAP clients and embedded devices support TLS 1.2+ and disable legacy endpoints before the July deadline.
A worldwide Outlook.com sign-in outage left some users signed out or seeing 'too many requests' errors; Microsoft says iPhone users must manually re-enter their credentials in the Mail app to regain access. Service health returned to normal by around 7 PM UTC, but the root cause and regional impact were not disclosed. The incident follows other recent Exchange Online/microsoft 365 sign-in outages across Microsoft services.
Microsoft reports an Exchange Online outage blocking mailbox/calendar access across multiple connection methods; by 14:20 EDT the outage was mitigated, but a separate MO1253428 issue affecting Office.com and Copilot sign-in is still under investigation, with post‑incident details forthcoming.
Microsoft says an ongoing Exchange Online incident is caused by a new URL rule that erroneously flags legitimate messages as phishing and quarantines them, disrupting mail flow. The company is reviewing quarantined emails and working to unblock legitimate URLs, with some users potentially seeing previously flagged messages delivered as remediation proceeds; Microsoft has not provided scope or regional impact details yet.
Microsoft says it is investigating a service incident affecting Exchange Online, Teams, and the Microsoft 365 suite (MO1220495) that began on Jan 21, 2026, with users experiencing connectivity and sign-in issues. An Update later pointed to a possible third-party networking issue as the root cause. By the latest statements, access issues were resolved and the service environment remained healthy, but admins should monitor the Microsoft 365 Service Health Dashboard for tenant-specific impact and further updates.
Microsoft 365 is experiencing issues affecting Exchange Online and Microsoft Teams, causing potential outages for users of Outlook and Teams. The company is working to resolve the problem but is facing delays, acknowledging the significant impact on businesses. User reports on Downdetector indicate a spike in problems around 1 p.m. EST, with some users unable to access services since the morning. Microsoft is actively investigating the issue and providing updates.
Microsoft is investigating an ongoing outage in its Exchange Online service, which is causing customers to be unable to send emails and receive "503 5.5.1 Bad sequence of commands" errors. The issue is related to a recent change in the free/busy infrastructure. Microsoft is working on resolving the problem and has removed the incident from the admin center, but some users are still experiencing issues. The outage has impacted users in various regions, including the United States, Europe, India, and the United Kingdom. This is not the first time Microsoft has faced issues with its email services, as previous outages have occurred in Outlook.com and Exchange Online.
Microsoft is investigating an ongoing issue that is preventing some customers from accessing their Exchange Online mailbox through Outlook on the web. The outage is impacting users in North America and South America. Microsoft is analyzing recent deployments to locate the root cause of the issue and is testing a new fix after an initial one failed to recover the service as expected.
Microsoft has extended the deadline for the use of Client Access Rules (CARs) in Exchange Online until September 2024 for some companies that are unable to migrate to the more secure Azure Active Directory Conditional Access and Continuous Access Evaluation (CAE) approach. The shift from CARs to Conditional Access and CAE is not a simple matter, and Microsoft has already begun taking steps to move organizations to Conditional Access and CAE. CAE became generally available in January 2022 as a key part of Microsoft's larger Azure AD Zero Trust Session Management portfolio, with Redmond highlighting the tool's security enhancements and real-time enforcement.
Microsoft has delayed the deprecation of Client Access Rules (CARs) in Exchange Online until September 2024, a year later than previously announced. CARs are used to filter client access to Exchange Online using various factors, including IP addresses and authentication type. Microsoft is encouraging customers to migrate to more secure alternatives such as Azure Active Directory conditional access and continuous access evaluation. The delay was prompted by the need for proper support in some cases, and Microsoft is waiting for customers to request help migrating their CARs to the new access control options via support tickets.
Microsoft is introducing a new Exchange Online security feature that will automatically start throttling and eventually block all emails sent from "persistently vulnerable Exchange servers" 90 days after the admins are pinged to secure them. The new system's primary goal is to help Exchange admins identify unpatched or unsupported on-prem Exchange servers, allowing them to upgrade or patch them before they become security risks. This new enforcement system will only affect servers running Exchange Server 2007 using OnPremises connectors to send mail to allow fine-tuning before expanding to all Exchange versions, regardless of how they connect to Exchange Online, after tuning.