An unspecified security incident at cloud provider Rackspace that appears to have begun on Saturday Australian time and which took out the company's hosted Microsoft Exchange service remains unresolved three days on.
Rackspace, which boasts that it has an "award-winning fanatical support team", has not provided further details on the security incident but said it has taken down its Hosted Exchange product.
Nor has Rackspace given an estimated time of service restoration, saying only that "this will continue to be an extended outage of Hosted Exchange".
The best solution according to Rackspace is for customers to move to Microsoft 365.
Rackspace said it will provide Microsoft Exchange Plan 1 licenses on Microsoft 365 until further notice, for free.
Whether or not customer data is compromised remains unclear.
Rackspace said those with a hybrid hosted environment with the company's Email service and Exchange on a single domain will need to move all mailboxes to M365 for email to work properly.
The company warned that customers must not delete their original mailboxes when moving them to M365, in order to preserve data.
Rackspace has not said how many customers are affected by the outage.
The cloud provider said it has "been able to successfully restore email services to thousands of customers on Microsoft 365".
A temporary fix for the outage can be implemented, by rerouting email destined for Hosted Exchange users to external email addresses while customers move to Microsoft 365, Rackspace said.
As of writing, Rackspace reports on its customer facing service status dashboard that the Hosted Exchange, MAPI/RPC, POP and IMAP mail retrieval, SMTP message transfer, Outlook Web Access (OWA), and the ActiveSync mobile data synchronisation are all down.
Rackspace is a listed as a provider on the NSW government's cloud purchasing arrangements panel since July this year.
