Migrating Your Email from Rackspace to Microsoft 365

This guide outlines the process of moving your email data from Rackspace IMAP to your new Microsoft 365 (Outlook Cloud) environment. Following these steps ensures a smooth transition with minimal downtime.

🛡️ Phase 1: Preparation & Requirements

To ensure the migration runs without errors, please confirm the following:

• Microsoft 365 Licenses: Every user must have an active Microsoft 365 license (e.g., Business Basic, Standard, or Premium) with an active mailbox.
• Rackspace Credentials: We require the full email address and password for every account being migrated.
  • Note: If you have Multi-Factor Authentication (MFA) enabled on Rackspace, you may need to generate an "App Password" specifically for the migration.
• Mailbox Size: Ensure your Microsoft 365 mailbox limit (usually 50GB) is larger than your current Rackspace storage.

⚙️ Phase 2: Server Connection Settings

Microsoft 365 will use the following "Migration Endpoint" settings to pull your data from Rackspace:

📥 Phase 3: The Migration Workflow

The migration happens in the background while you continue to work.

1. Creating the Migration Batch: We group your users into a "Migration Batch" within the Microsoft 365 Admin Center.
2. Initial Sync: Microsoft begins copying all folders and emails from Rackspace.
   • What Migrates: All email messages and your folder hierarchy.
   • What Does NOT Migrate: Contacts, Calendars, and Tasks. These are stored locally in Rackspace and must be exported as .pst or .csv files and imported into Outlook manually.
3. Incremental Syncs: Once the initial copy is done, Microsoft will continue to sync every 24 hours to catch any new emails arriving at Rackspace.

🏁 Phase 4: The "Cutover" (The Final Switch)

When we are ready to officially switch to Microsoft 365:

1. MX Record Update: We update your domain’s DNS records to point to Microsoft. From this moment, all new incoming mail arrives in your Outlook Cloud inbox.
2. Final Sync: We perform one last "Sync" to grab any remaining emails from the Rackspace server.
3. Completing the Batch: Once verified, we stop the migration batch and "finalize" the process.

⚠️ Critical Notes for Users

• Outlook Profile Setup: After the switch, you will need to create a new Outlook profile on your desktop app. Your old Rackspace profile will no longer receive new mail.
• Folder Limits: Microsoft 365 has a limit of 10,000 items per folder for optimal performance. If you have extremely large folders, consider archiving some mail before we begin.
• Attachment Limit: The default maximum size for individual items is 150MB (significantly higher than Google's 25MB limit).

📞 Support & Getting Started

Once the cutover is complete, you can access your email via the web at outlook.office.com or by signing into the Outlook desktop application with your Microsoft credentials.