Rackspace’s hosted Microsoft Exchange environment was hit by a “security incident”. The services were initially taken offline, but have since been partly restored through a detour in Microsoft 365.

Rackspace announced that its Hosted Exchange environment was hit by a “security incident” last Friday. Rackspace decided to take the services offline for further investigation into the scope and impact of the incident.

The incident reportedly occurred in an isolated segment of Rackspace’s Hosted Exchange environment. The cause was not confirmed.

Rackspace provided affected customers with access to Microsoft Exchange Plan 1 licenses on Microsoft 365 for the duration of the incident. Rackspace also allows users to forward emails for Hosted Exchange users to an alternative email address.

Meanwhile, Rackspace says it has restored email services to thousands of customers through Microsoft 365. Some customers remain locked out and the restoration process is ongoing.

Microsoft 365 detour

According to Rackspace, rerouting through Microsoft 365 is currently the best option for restoring incoming email service and temporarily forwarding emails to an alternative email address.

Rerouting through Microsoft 365 is not an easy task. The alternative path has to be configured manually. The process is especially time-intensive for users of hybrid Hosted Exchange environments, where Rackspace Email and Exchange reside on a single domain.

For the email flow to work properly, all mailboxes have to be migrated from Rackspace Email and Exchange to Microsoft 365. To preserve data, it’s important that users do not delete their original mailboxes when moving to the alternative address.

Rackspace notes that support waiting times are currently very long. At the time of writing, it’s unclear when the issues in Rackspace Hosted Exchange will be resolved.

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