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ZDNET's key takeaways
- Legitimate emails in Exchange Online are being tagged as spam.
- A new URL rule is quarantining emails as phishing attempts.
- Microsoft has made some progress resolving the problem.
Those of you who use Microsoft's Exchange Online as your email service may find that important emails are failing to appear in your inbox. Late last week, the software giant acknowledged a problem with the online version of Exchange, causing legitimate emails to be quarantined as spam.
In a service alert spotted by BleepingComputer, Microsoft revealed that the glitch started on February 5 and has been preventing some Exchange Online users from sending and receiving emails.
“Some users' legitimate email messages are being marked as phish and quarantined in Exchange Online,” Microsoft said in the service alert. “We've determined that the URLs associated with these email messages are incorrectly marked as phish and quarantined in Exchange Online due to ever-evolving criteria aimed at identifying suspicious email messages, as spam and phishing techniques have become more sophisticated in avoiding detection.”
The company pinned the blame on a new URL rule that's incorrectly identifying some legitimate URLs as malicious. That glitch is triggering false positives, where Exchange is tagging emails from those domains as phishing attempts.
Microsoft has made some progress in resolving the issue. At this point, some users may see previously quarantined emails start to appear in their inboxes. But other messages will remain quarantined until the problem is completely fixed.
If you do use Exchange Online and are affected by this bug, you may want to check your quarantined emails to see if any legitimate ones are waiting for you. To do this, head to the Quarantine page for Microsoft Defender and make sure you're signed in with your work or school account. If you spot a message that's legit, just check it and click the Release button to free it from quarantine jail. Otherwise, you'll have to wait for Microsoft to fully resolve the glitch, which hopefully won't take too much longer.
Why would a problem like this occur? Blame it not just on Microsoft but on today's sophisticated breed of spammers and scammers. As junk emails and phishing attacks become more advanced, they get better at evading detection. That means companies like Microsoft have to continually tweak the rules designed to identify and block them. In this case, Microsoft apparently went a bit overboard.
