What security features should you look for in a Microsoft 365 tenant-to-tenant migration tool?

Our company is preparing for A tenant-to-tenant (T2T) migration, and while performance and migration speed are important, our security team is far more concerned about how the migration tool handles authentication, data transfer, and compliance. There are plenty of migration solutions available, but not all of them explain how they protect organizational data during the migration process.

I've been evaluating the MacSonik Office 365 Tenant-to-Tenant Migration solution, and its security-focused approach is one of the main reasons it made our shortlist. Instead of relying on legacy authentication methods, it uses OAuth 2.0 with Microsoft Graph API, which aligns with Microsoft's modern authentication standards. That gives us more confidence that we're using a supported and secure approach for accessing Microsoft 365 resources.

Another aspect I appreciated is that all data transfers take place over TLS-encrypted HTTPS connections. Since our organization deals with confidential client information, encrypted communication is non-negotiable during any migration project.

One feature that stood out is that the software runs entirely on the administrator's local system. Unlike some cloud-based migration platforms, it doesn't upload or store organizational data on external servers. From both a privacy and compliance perspective, that's a significant advantage because our IT team maintains complete control over where company data is processed throughout the migration.

The tool is also Microsoft 365 GCC compliant, which is an important consideration for organizations operating under strict governance, regulatory, or compliance requirements. Having a migration solution that works within Microsoft's supported ecosystem makes long-term maintenance much easier.

Beyond security, the software supports migration of Exchange Online mailboxes, shared mailboxes, OneDrive accounts, SharePoint sites (drives and lists), contacts, and calendars. It preserves folder hierarchy, metadata, email formatting, attachments, document properties, and OneDrive structures, helping ensure users experience minimal disruption after moving to the new tenant.

For administrators, the migration controls also appear comprehensive. You can perform mailbox mapping, select specific workloads, migrate individual folders, apply custom date-range filters, and filter SharePoint or OneDrive content by file size, extension, or content type. Those options help reduce unnecessary data transfer while giving better control over the migration process.

The built-in deduplication capabilities for Exchange Online, SharePoint, and OneDrive are another plus. By identifying duplicate emails and files through metadata and hash-based analysis, the software minimizes redundant data while preserving the integrity of the remaining content. Combined with the Skip Previously Migrated feature, incremental synchronization becomes much more efficient because only newly added or modified items are transferred during subsequent migration cycles.

I also like the reporting features. Real-time dashboards provide visibility into migration progress, completed tasks, skipped items, and any errors that require attention. Detailed migration reports can then be used for auditing, compliance documentation, and post-migration verification, which is something our IT governance team specifically requested.

For those who've completed A tenant-to-tenant (T2T) migration, which security capabilities mattered most when selecting your migration solution? Did modern authentication, local data processing, encryption, compliance certifications, or detailed audit reporting influence your decision more than migration speed itself?