A malfunction in Microsoft’s anti-spam service is mistakenly flagging legitimate URLs as malicious, preventing users from opening links in Exchange Online and Microsoft Teams. The issue, which began on September 5th, has also caused numerous emails to be wrongly quarantined. Administrators have been receiving false alerts about potentially harmful URL clicks, despite the links being safe.
Microsoft identified over 6,000 affected URLs and is working to unblock them while replaying messages that were incorrectly trapped. Although a partial fix has been deployed to prevent further quarantining, engineers are still addressing a newly identified subset of problematic URLs. The company has acknowledged that while most of the impact has been resolved, some residual issues remain as root cause analysis continues.
This incident is part of a recurring pattern where updates to Microsoft’s automated filtering systems have led to widespread false positives. Earlier this year, similar bugs incorrectly flagged emails from Gmail and Adobe as spam, highlighting ongoing challenges in the company’s email security systems.
Read more...