Rackspace is dealing with a “security incident” involving its Hosted Exchange service, prompting the company to shut the service down.

Rackspace first became aware of the issue on Friday, December 2. The company acknowledged the issue on its incident report page:

On Friday, Dec 2, 2022, we became aware of an issue impacting our Hosted Exchange environment. We proactively powered down and disconnected the Hosted Exchange environment while we triaged to understand the extent and the severity of the impact. After further analysis, we have determined that this is a security incident.

The company updated its report Sunday, saying it was working on the problem but customers should considering using Microsoft 365 in the meantime:

We continue to make progress in addressing the incident. The availability of your service and security of your data is of high importance. We have committed extensive internal resources and engaged world-class external expertise in our efforts to minimize negative impacts to customers. We will continue to report our progress and update you as we have more information that we can share.

In order to best protect the environment, this will continue to be an extended outage of Hosted Exchange. At this time, moving to Microsoft 365 is the best solution for customers, and we highly encourage affected customers to move to this platform. Since our last update, we have been able to successfully restore email services to thousands of customers on Microsoft 365.