IS&T addresses email service disruptions
December 6, 2018
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Earlier this week, email services at MIT were impacted by malicious network traffic focused on security infrastructure systems.

This caused delays in delivery of email between both the and domains and addresses outside MIT. Email delivery within MIT remained unaffected.

In response, Information Systems and Technology (IS&T) migrated email security infrastructure to a cloud-based platform, Microsoft Office 365 (O365). The infrastructure change impacted some third-party mass email services used by the community; IS&T is investigating the issue.

What happened

Early Monday, December 3, a distributed denial of service (DDoS) attack on MIT's email security infrastructure began.

Initially, IS&T worked to expand resources available to the affected systems, but this did not mitigate the impact.

By early afternoon, IS&T decided to migrate MIT’s incoming email infrastructure to Microsoft’s cloud-based Office 365 platform. Microsoft’s cloud service was already in use at MIT for its Office Online features, as well as for email and calendaring within IS&T. Leveraging Exchange Online Protection’s tools and scalability to mitigate this incident accelerated work that had already been planned. While email security was transferred to Microsoft’s service, MIT’s Exchange mailboxes remain unchanged.

By 5pm, all incoming MIT email was directed through Microsoft’s security infrastructure service, and messages that had been queued resumed delivery. Although email delivery was delayed, IS&T observed no data loss.

On Tuesday, attacks resumed on the email forwarding service. By 6pm, all email for addresses was also directed through Microsoft's security service.

Next steps

With email security now being handled by Microsoft's cloud service, IS&T is adjusting spam and bulk email filters, and actively updating documentation in the Knowledge Base to reflect this week's changes. This FAQ contains information about managing spam and bulk email, as well as related topics, and will be updated as new information is available.

If you have questions or concerns, contact the IS&T Service Desk.

Note: This post was updated on December 7, 2018, to include mention of the impact on mass email delivery and a link to the FAQ.