Rackspace to Office 365 Email Migration

Rackspace customers can have different source environments, including Rackspace Email, Hosted Exchange, or a Microsoft 365 tenant. Choose the migration method that matches the source service rather than treating every Rackspace mailbox as the same type of migration.

For Rackspace Email, use the EdbMails IMAP Migration Tool. Rackspace documents the secure IMAP endpoint as secure.emailsrvr.com on port 993 with SSL. For Rackspace Hosted Exchange, use the Hosted Exchange migration workflow. For a Rackspace Microsoft 365 tenant that is moving to a different Microsoft 365 tenant, use the Office 365 tenant-to-tenant workflow.

Standard IMAP migration is email-focused and does not move contacts, calendars, tasks, SharePoint, OneDrive, Teams, or other non-mail workloads. Hosted Exchange and Microsoft 365 tenant migrations have different capabilities, prerequisites, and licensing, so keep those methods separate during planning.

EdbMails provides separate workflows for Hosted Exchange migration, Microsoft 365 tenant-to-tenant migration, and IMAP to Office 365 migration. This page routes Rackspace customers to the correct method based on their actual source platform.

Where the selected workflow supports it, automatic mailbox mapping can reduce repetitive setup by matching available source and target identifiers. Administrators should still review the final mapping before migration, especially when addresses, aliases, or mailbox types differ.

1. Rackspace to Office 365 Migration Planning

   1. Identify the Rackspace source: Rackspace Email (IMAP), Rackspace Hosted Exchange, or Rackspace Microsoft 365.
   2. Inventory mailboxes, mailbox sizes, aliases, archives/shared mailboxes, permissions, and any non-mail workloads.
   3. Choose the matching EdbMails migration workflow. Do not use the IMAP path for Hosted Exchange or Microsoft 365 tenant data if you need Exchange-specific mailbox content.
   4. Create/provision the Microsoft 365 destination users/mailboxes and assign the required licenses.
   5. Add/verify the custom domain and plan DNS/MX/Autodiscover changes.
   6. Review source limits, Microsoft 365 throttling, message-size limits, bandwidth, and migration-computer capacity.
   7. Run a pilot, verify the target, and then perform production migration plus follow-up passes where supported.

2. Why Choose Microsoft 365 Over Rackspace?

   Microsoft 365 delivers a complete productivity and collaboration platform, while Rackspace is primarily focused on email hosting. With Microsoft 365, you get integrated apps like Outlook, Teams, Word, Excel, SharePoint, and OneDrive, enabling real-time communication and file sharing. It offers larger mailbox storage, 1 TB of cloud space per user, enterprise-grade security, and automatic updates, ensuring reliability and data protection. Accessible from any device, Microsoft 365 provides the flexibility, scalability, and collaboration tools modern businesses need, making it a clear upgrade from Rackspace’s traditional email services.

3. Rackspace to Office 365 Migration Prerequisites

   Rackspace Email (IMAP)

   • Rackspace documents secure.emailsrvr.com as the secure IMAP server, port 993, with SSL.
   • Collect mailbox addresses and credentials and prepare the EdbMails CSV for bulk migration.
   • Standard IMAP moves email/mail folders only; contacts, calendars, notes, and other non-mail data require another method.

   Rackspace Hosted Exchange

   • Confirm the hosted Exchange connection method, source version, Autodiscover/EWS access, mailbox permissions, and whether primary/archive/public-folder data is required.
   • Use the EdbMails Hosted Exchange migration workflow rather than the IMAP path when Exchange mailbox data beyond basic email is required.

   Rackspace Microsoft 365

   • If moving mailbox data to a different Microsoft 365 tenant, prepare both tenants and use the EdbMails tenant-to-tenant workflow.

   Microsoft 365 target

   • Create/provision users and assign licenses, add/verify the custom domain, use the current EdbMails OAuth-based target connection, and run a pilot before production migration.

4. Steps to Migrate from Rackspace to Office 365

   EdbMails supports secure and guided migration from Rackspace to Office 365 using multiple migration methods. Select the appropriate method below based on your source environment and migration requirements.

   Method 1: Migrate from Rackspace Hosted Exchange to Office 365

   Method 2: Migrate from Rackspace Office 365 Tenant to Office 365

   Method 3: Migrate from Rackspace to Office 365 using an IMAP connection

   Method 1 : Migrate from Rackspace Hosted Exchange to Office 365

   • Step 1: Download and Install EdbMails Exchange migration software

     • Download and Install EdbMails on any Windows-based computer that is connected to the source Exchange server.

        System requirements for Hosted Exchange to Office 365 migration

       

     • Start the EdbMails application on your computer.
     • Enter your registered email ID and password, then click ‘Login’. If you are accessing EdbMails for the first time, choose ‘Start Your Free Trial’ to continue with the trial version.
       Note: The trial version lets you migrate all mailboxes with 30 items per folder. For migrating all the items, purchase Live Exchange migration license from EdbMails website.

         Click here to know the live Exchange Migration Pricing Details.

       Once the purchase is completed, close the software and reopen it. Log in again with the same email ID and password used during the purchase to activate the license.

       

     • Select 'Live Exchange migration' option.

       

     • Select the ‘Live Exchange to Office 365 Migration’ option to initiate the guided migration process from your Rackspace Hosted Exchange to Office 365

       

     • You can keep the default job name or select ‘New Job’ to create a custom name, making it easier to identify and manage your migration tasks efficiently.

       

   • Step 2: Connect to source Rackspace Hosted Exchange

     • To create a new connection with the source Exchange server, select ‘Add New Connection’. If a connection has already been set up previously, choose it from the available list and click ‘Connect to Existing’ to proceed.

       

     • Choose ‘Connect to Hosted Exchange Server’ when your server is a hosted Exchange server or when you need to migrate an individual mailbox.
     • EdbMails provides flexible migration options, allowing you to migrate primary mailboxes, archive mailboxes, and public folders guidedly in a single solution.

        Various methods for establishing a connection to your Hosted Exchange server.

        With EdbMails, you can migrate mailboxes, public folders, and archive mailboxes from Hosted Exchange to Office 365.

     • Choose the required connection options and click the ‘Next’ button.

       

     • Select the appropriate option to perform ‘Multiple User Migration’ or ‘Single User migration’.

        Different options to connect to Hosted Exchange server

     • Click the ‘Next’ button to continue.

       

     • Choose ‘Connect Using Autodiscover Email’ to set up the connection with your Hosted Exchange server by entering your email address and password, provided that the Autodiscovery service is enabled on the server, allowing the connection to be configured automatically using your login credentials.
     • Alternatively, use 'Default Connection' to connect via the server's domain name or IP address.

       

     • Enter the required details of the source Hosted Exchange server, then click ‘Login’ to authenticate and establish the connection.

       

     • After successful authentication, choose any one of the following options to load the mailboxes:
       1. i) Load Mailboxes Automatically: EdbMails loads and displays the mailboxes automatically once you sign in, simplifying the configuration process. Due to Microsoft API restrictions, it may display only up to 100 mailboxes. If your environment contains more than 100 mailboxes, use the alternative option below.
       2. ii) Load Mailboxes using CSV file: If the automatic method does not retrieve all mailbox names, select the ‘Load Mailboxes using .CSV file’ option to manually import and load the required mailboxes.
       3. iii) Load Mailboxes from previous list: Quickly access the mailboxes from the previously saved list imported during your last session.
     • Choose ‘Load Mailboxes Automatically’ and click ‘Next’ to continue.

       

   • Step 3: Select source Rackspace Hosted Exchange mailboxes

     • Choose the specific mailboxes folders you wish to migrate to the destination Office 365 server, ensuring they are appropriate for the migration process.

       

   • Step 4: Connect to the target Office 365 server

     • Select ‘Add New Connection’ to create a new connection with your target Office 365 account.
     • If you have already configured a connection, choose it from the list and click ‘Connect to Existing’ to proceed.

       

     • EdbMails provides flexible migration options that allow you to guidedly migrate primary mailboxes, archive mailboxes, and public folders, all through a single, comprehensive solution.
     • Choose the appropriate connection settings and click the ‘Next’ button to proceed.

       

     • Choose any of the available options to create a secure connection using OAuth 2.0 modern authentication.
     • Select Auto Registration for a quick and hassle-free setup. Simply sign in with a Global Admin account and approve the required permissions to automatically register the application in Azure AD.
     • Or select Manual Registration if you prefer to provide the Azure AD application details yourself. This method supports both Global Admin accounts and accounts with Full Access permissions.
     • Click ‘Login’ to proceed.

       

     • Authenticate on the Microsoft sign-in page.

       

     • Choose a method to load the mailboxes. Either select ‘Load Mailboxes Automatically’, 'Load Mailboxes using .CSV file’ or ‘Load Mailboxes from previous list’.
     • Then, click the ‘Next’ button.

       

   • Step 5: Rackspace Hosted Exchange to Office 365 mailboxes mapping

     • Choose the required mailbox mapping option to map source mailboxes or folders to the respective target mailboxes or folders.

       

     • EdbMails automatically creates mailboxes on your target Office 365 server.

        Learn more about the automatic mailbox creation process on the target Office 365 server.

       

   • Step 6: Start Rackspace Hosted Exchange to Office 365 migration

     • Click the 'Start Migration’ button to initiate the migration process.

       

     • Monitor the migration progress using the progress bar. Once the migration is complete, EdbMails will prompt you to review the status. Click the ‘View Logs’ button to access the migration report.

       

   Method 2 : Migrate from Rackspace Office 365 Tenant to Office 365

   • If you have your Office 365 tenant on Rackspace, then an Office 365 to Office 365 migration is the best approach.
   • Download and install EdbMails on your computer and follow the below steps.

   • Step 1: Select and Configure Office 365 to Office 365 Migration

     • Select ‘Office 365 to Office 365 Migration’

       

     • Keep the default job name, or click the ‘New Job’ button to create a custom name of your choice.

       

   • Step 2: Connect to source Rackspace Office 365 tenant

     • Click the ‘Add New Connection’ button to establish a new connection to the source Office 365. To use the previous connection, select it from the connection list and click the ‘Connect to Existing’ button to proceed.

       

     • EdbMails delivers versatile migration features that enable you to move primary mailboxes, archive mailboxes, and public folders smoothly using a single, unified solution.
     • Choose the required connection options and click the ‘Next’ button.

       

     • Choose the secure authentication method you want to use for the target Office 365 account.
     • You will then be redirected to the official Microsoft sign-in page, where your credentials are securely validated through OAuth 2.0 for safe and protected access.
     • Click ‘Login’ to proceed.

       

        Connect to Office 365 server using secure modern authentication

     • Authenticate on Microsoft sign-in page.

       

     • After successfully connecting to your Office 365 server, select an option to load the mailboxes. Alternatively, you can also load the mailboxes using a CSV file.

       

   • Step 3: Select source Rackspace Office 365 tenant mailboxes

     • Select the mailboxes you want to migrate from the source Office 365 server.
     • Click ‘Next’ to proceed.

       

   • Step 4: Connect to target Office 365 server

     • Select ‘Add New Connection’ to create a fresh connection with the target Office 365 account. If you have already set up a connection earlier, choose it from the list and click ‘Connect to Existing’ to continue.

       

     • Select the required connection options and click the ‘Next’ button.

       

     • Select the appropriate target connection method.
     • Click the ‘Login’ button to continue.

       

     • Authenticate on Microsoft sign-in page.

       

     • Select one of the methods to load the mailboxes. You can also load the mailboxes using a CSV file.

       

   • Step 5: Map source and target mailboxes

     • Choose the required mailbox mapping option

       

     • After successfully creating mailboxes on your target server, EdbMails automatically maps mailboxes and folders between source and target tenants, which is particularly beneficial for large-scale migrations. Alternatively, you have the flexibility to manually map source folders and subfolders to specific target locations as needed.

       

   • Step 6: Start Office 365 to Office 365 migration operation

     • Click the 'Start Migration’ button to initiate the migration process.

       

     • EdbMails will automatically initiate the migration and notify you once it's complete. You can review the migration details in the migration log report provided. Additionally, if needed, you have the flexibility to pause or resume the migration at any time.

       

   Method 3: Migrate Rackspace Email to Office 365 with IMAP

   • Step 1: Download and Install EdbMails IMAP migration software

     • First, download and install EdbMails on your computer running on Windows operating system. Once installed, launch the application and choose the ‘IMAP Migration’ option from the main dashboard to proceed with the migration setup.
     • Select ‘IMAP to Office 365 Migration’.

       

   • To connect a single Rackspace Email mailbox, select ‘Single User / Account Migration’, choose ‘Connect to IMAP Server’, and click ‘Next’.

     

   • Step 3: Select source Rackspace server mailboxes

     • Choose the specific mailboxes or individual folders you wish to migrate. Once your selection is complete, click ‘Next’ to continue.

       

   • Choose the required method to load target Microsoft 365 mailboxes. If the automatic list does not include every required mailbox, use the supported CSV-loading option and verify the target list before continuing.
   • EdbMails can automatically map matching source and target mailboxes and also allows manual mapping. Review each mapping before starting the migration.

     

   • Step 6: Start Rackspace to Office 365 migration

     • Once the mailboxes are mapped, click the 'Start Migration' button to begin the migration process.

       

     • Click the 'View Logs' button to access the migration report, which provides detailed information on the items migrated from each folder and mailbox. The report includes mapping details, the number of emails migrated, and any issues encountered during the migration process, helping you track and verify the migration of your data.
     • Also log into your target server to verify the migrated items.

       

5. Rackspace to Office 365 Post Migration Tasks

   • Verify the destination

     Review migration reports and verify representative mailboxes, folders, messages, attachments, and user access before changing production mail flow.

   • Update DNS/MX when Microsoft 365 becomes the production destination

     Change the required DNS records only after the target environment is validated.

   • Validate Outlook/client access

     Confirm Microsoft 365 sign-in and Autodiscover behavior. Recreate Outlook profiles only where required.

   • Retain the Rackspace source during validation

     Keep the source available for the agreed transition period before canceling or decommissioning services.

6. Troubleshooting Guide for Rackspace to Office 365 Migration

   Hosted Exchange to Office 365 migration feature:

   For troubleshooting, visit Knowledge Base articles.

   For more queries, check Frequently Asked Questions or contact support.

   Office 365 to Office 365 migration feature:

   1. Knowledge Base.
   2. Frequently Asked Questions

   IMAP to Office 365 migration feature:

   1. Knowledge Base.
   2. Frequently Asked Questions

 Learn more about the EdbMails IMAP Migration Tool.

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Additional resources:

• IMAP to Office 365 migration
• Office 365 tenant-to-tenant migration
• Exchange migration
• EdbMails IMAP migration software
• IMAP migration FAQ