Migrating a shared mailbox to Microsoft 365 (Exchange Online) is crucial to modernizing your business communications. Shared mailboxes enable multiple users to manage and respond to emails sent to a single address, like moc.ynapmoc@ofni or moc.ynapmoc@troppus. Shared mailboxes are integral to many organizations, especially in support, HR, and finance departments. As organizations move to cloud-based solutions, migrating these mailboxes becomes necessary, but it’s not always easy.
In this updated 2025 guide, we’ll walk you through the process step-by-step, address common problems, and suggest a trusted tool to make your transition seamless.
Why Shared Mailbox Migration Matters?
Shared mailboxes store critical team communications and are often accessed by multiple users. During a migration to Microsoft 365, overlooking these mailboxes can lead to lost data, broken permissions, and downtime that impacts collaboration. That’s why handling them with the same care as user mailboxes is crucial.
Pre-Migration Checklist
Before you begin, make sure:
- All users have Microsoft 365 licenses.
- You’ve taken a full backup of existing mailboxes.
- Your domain is verified in Microsoft 365.
- Admin credentials for both source and destination are ready.
- Exchange Online and on-prem Exchange environments are healthy.
- Auto-mapping and permission delegation are reviewed.
Common Problems Users Face During Shared Mailbox Migration:
Before diving into the steps, let’s identify the most frequent issues IT admins encounter:
- Loss of Access/Permissions
Post-migration, users may lose “Send As,” “Send on Behalf,” or “Full Access” permissions, leading to confusion and support tickets.
- Shared Mailboxes Not Appearing in Outlook
Mailboxes might not auto-map or appear correctly in Outlook or OWA, especially if permissions weren’t reconfigured.
- Mailbox Size Limits and Throttling
Large shared mailboxes can trigger Microsoft’s throttling policies, causing timeouts or partial data migration.
- Broken Folder Structure
Folder hierarchies and metadata like read/unread status or flags may not be preserved using native methods.
- Manual Mapping of Mailboxes
Without automation, mapping mailboxes one by one becomes tedious and error-prone.
- Unexpected Downtime
Lack of scheduling features in native tools can lead to unplanned downtime during business hours.
- No Detailed Reporting
Admins are often left guessing which mailboxes migrated successfully without a proper report.
- Complex PowerShell Commands
Many shared mailbox migrations rely on scripting, which can be error-prone and intimidating for non-experts.
- Failure to Migrate Archive or Inactive Mailboxes
Microsoft tools often ignore archives or inactive mailboxes unless explicitly included.
- Hybrid Environment Confusion
Syncing shared mailboxes becomes even more complex for on-premises Exchange + Microsoft 365 hybrid setups.
Step-by-Step: How to Migrate Shared Mailboxes to Microsoft 365
Step 1: Plan the Migration
- List all shared mailboxes to be migrated.
- Check mailbox sizes and user permissions.
- Determine if you’re migrating from on-prem Exchange or a different source.
Step 2: Choose the Right Migration Method
You have two primary choices:
- Native Methods: PowerShell scripts, Exchange Admin Center, and Hybrid Configuration Wizard.
- Third-Party Tools: GUI-based tools like the Shoviv Exchange Migration Tool are designed to simplify complex migrations.
Step 3: Backup Mailboxes
Always take a full backup of mailboxes before initiating migration. This ensures data recovery in case of any interruption.
Step 4: Prepare Microsoft 365 Environment
- Create shared mailboxes in Microsoft 365.
- Assign licenses if needed (though shared mailboxes typically don’t require a license under 50GB).
- Pre-assign required permissions to users.
Step 5: Start the Migration Process
- Using Native Tools:
-
- Export shared mailboxes to PST using PowerShell.
- Use Outlook or Import services to load PST into the new shared mailbox.
- Using the Shoviv Exchange Migration Tool:
- Select source and destination mailboxes.
- Use automatic mapping for faster setup.
- Enable incremental sync to skip already migrated data.
- Schedule the migration during off-hours to avoid downtime.
Step 6: Post-Migration Validation
- Verify mailbox access in Outlook and OWA.
- Check folder structure, message count, and metadata.
- Confirm that permissions are properly assigned.
Step 7: Generate Reports
If using a tool like Shoviv, generate detailed reports to ensure all items were successfully migrated. These help with audit trails and IT documentation.
Why Use a Professional Migration Tool?
Manual methods work, but only to a point. As the complexity and volume of shared mailboxes increase, tools like the Shoviv Exchange Migration Tool provide a safer and more efficient experience:
- Automatic and manual mailbox mapping
- Public folder and archive migration support
- Real-time migration tracking
- No size limits or data loss
- Schedule-based migrations and incremental sync
Final Thoughts:
Shared mailboxes are vital to business communication, and migrating them without disruption should be a top priority. While native options are free, they come with limitations that can cost more time, effort, and mistakes. A well-planned migration, backed by a robust tool, can make all the difference.
If you’re planning your migration in 2025, don’t leave shared mailboxes behind. Treat them with the same importance as user mailboxes, and leverage the right strategy to ensure a seamless experience.
Explore more on this topic in our detailed blog:
Migrate Shared Mailbox to Microsoft 365 – Step-by-Step
Frequently Asked Questions (FAQs)
Q1: Do shared mailboxes need licenses in Microsoft 365?
A: No, unless their size exceeds 50 GB or an archive is enabled.Q2: Can I migrate only shared mailboxes using Shoviv?
A: Yes, Shoviv allows you to select and migrate shared mailboxes exclusively.Q3: Will mailbox permissions migrate automatically?
A: Only with some hybrid setups. Otherwise, reassign permissions post-migration.