SparkPost: We are observing an elevated rate of spam foldering and open rates for messages destined to Office 365 domains
Timeline of updates
- resolved
This incident has been resolved. Summary: Beginning last week we made a change to add a URL to the list-unsubscribe header to be compliant with new rule “one-click” unsubscribe requirements from Gmail and Yahoo. After this update, some customers started reporting an increase in [new] junk foldering of messages destined to Office 365 addresses - it appears they were flagged by Microsoft’s Defender filtering framework. We worked with Microsoft who made changes to address this issue. In addition, some customers reported a large increase in opens and clicks on Monday and Tuesday of this week that we believe were caused by some action by Microsoft - likely a reclassification or redelivery routine.
From SparkPost’s published incident history: for incidents before Rewindex began polling this status page, only the final update text is available.
Impact, status and times are the vendor’s own, as last archived. View on status.sparkpost.com (opens in new tab).