How to Migrate From Rackspace Hosted Exchange OST File to Microsoft 365

Summary: Rackspace is hit by a massive security incident that has led to email outage for most of its Hosted Microsoft Exchange customers across the globe. The article shares the details of the incident and solutions to quickly restore the email services with the help of the free Microsoft 365 E1 license provided by Rackspace and the user mailboxes to Microsoft 365 with the help of an OST to PST converter tool.

Update : 8th Dec’2023 – Rackspace has announced that their Hosted Exchange Environment is disrupted due to Ransomware and they are investigating on the same.

Source from Rackspace

As per the latest news, Rackspace has announced that their Hosted Exchange got compromised due to Ransomware attack, read the latest update & causing of disruption. Ransomware Hosted Exchange Outage

Rackspace-a cloud computing and hosting provider-has recently suffered a cyber-attack that took down its hosted Microsoft Exchange Servers and caused email outages for its customers across the globe. The incident first came to light last Friday, December 2, 2023.

Rackspace has also confirmed the security incident that led to a significant failure of their hosted Exchange environment and hence has been declared by Rackspace Hosted Exchange Outage; Read the solution. Meanwhile, Rackspace provides free access to the Microsoft 365 E1 license to the affected customers until further notice.

As per the last update received, the best solution recommended by Rackspace for the affected customers is to move or migrate to Microsoft 365. They said, “We have heard and understand that self-migration may not be simple and can be challenging to implement. Our customer support teams are working on a 24/7 basis to assist impacted customers.”

However, Customers desperately trying to contact Rackspace IT support are left in long queues for several hours.

Figure 1: Rackspace support ticket system is currently overloaded

The company has not mentioned how many Hosted Exchange customers have been affected. Also, there is no ETA provided by Rackspace for the resolution or when the issue will be resolved.

Figure 2: Rackspace Hosted Exchange Services are Down ( Update: Dec 8, 2023 Source Rackspace)

What You Can Do to Restore Email Service?

If your Rackspace Hosted Exchange Server is affected or email service is disrupted, you can apply the following solutions in the given order to restore the email services and migrate the users with their mailboxes to Microsoft 365 or Office 365 until Rackspace investigates and resolves the issue at their end.

Implement Temporary Email Forwarding

Rackspace is actively trying to restore the email services for the affected Hosted Exchange customers. However, it seems that there are thousands of affected customers that need help but are currently under a long queue.

If you are one of those still waiting for the resolution, you can use the free access to Microsoft 365 E1 provided by Rackspace to set up a Microsoft 365 tenant, create users, and temporarily forward all the emails to Microsoft 365.

Rackspace has shared a detailed document with stepwise instructions to set up the Microsoft 365 tenant and DNS for email forwarding.

This will help you restore the email services and allow users to send and receive new emails or messages. However, users won?t have access to their old mailbox or mail items. Continue reading to learn how to restore the user mailboxes to Microsoft 365.

Use the Rackspace Archive Service (If Subscribed)

The Rackspace Archive Service is unaffected and working. Thus, customers who have subscribed to the Archive Service for their users and mailboxes can use it to recover or download the emails into a PST file and then import the PST to Microsoft 365 profile. This way, you can restore the user mailboxes and provide them access to their old mail items.

This is a 3-step process:

Repeat the steps to find and export the emails of all users in PST format.

Next, you need to create a PST import job in Microsoft 365, upload the PST files to Azure Storage, map users with the .PST mailboxes, and then start the PST import job to restore user mailboxes.

Figure 3: Solutions shared by Rackspace

This is a long and tedious process that can take several hours for each user. However, this is also the best manual way of restoring the user mailboxes affected by Rackspace Hosted Exchange security incident to Office 365/Microsoft 365.

Rackspace customers who did not subscribe to the Archive Service before this security incident occurred cannot use the method to export emails or migrate user mailboxes to Microsoft 365.

However, you can extract mail items from users? local Outlook cache (.OST) files and export them to Microsoft 365 to restore the mailboxes. Refer to the next solution to learn more and quickly migrate the user mailboxes to Microsoft 365 with complete integrity.

Use an OST to PST Converter Tool for Faster Migration

When an Exchange Server fails or the user is disabled or removed from the server, the Outlook email profiles become inactive and inaccessible. However, Outlook configured with an Exchange profile (Hosted Microsoft Exchange in this case) creates a local cache  or .OST file to store a synchronized copy of all the mail items from the Exchange mailbox server to the local storage for quick access and improve Outlook performance.

Administrators can convert this local OST file of all users to PST format with the help of a reliable OST to PST converter tool, such as Stellar Converter for OST Technician Edition.

The software automatically locates the OST files on the system and displays them in a list for conversion.

The software also supports “Batch Conversion,” allowing administrators to select and convert multiple OST files to PST format simultaneously.

After the conversion, administrators can import the converted PST files to Microsoft 365 users? mailboxes through the Network Upload method or using Outlook Import/Export wizard.

You may also select and export the OST files of all users (one at a time) directly to their Microsoft 365 user?s mailbox in a few clicks. All you need is either the Microsoft 365 global administrator?s or users’ credentials.  

To Wrap up

Customers who subscribed to the Rackspace Archive Service can use the search option to find and export user mailboxes to PST files and then import the PST to Microsoft 365 using Network Upload or Drive Shipping method. But the process is quite long and tedious with multiple intermediate steps that can take several days or weeks to complete based on the number of users and mailbox size.

If you didn?t subscribe to the Rackspace Archive Service or want to save time and quickly migrate all users with their mailboxes to Microsoft 365, you can use an OST to PST converter software such as Stellar Converter for OST Technician Edition. It?s the most efficient way to migrate user mailboxes from the affected Rackspace Hosted Exchange Servers to Microsoft 365. All you need to do is select the local OST of the users and export them to their Microsoft 365 mailbox one by one with no intermediate steps.

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