Most migration horror stories begin the same way: The migration was completed, but no one checked these five items beforehand. After resolving over 1,000 migration issues across enterprise environments, i know where the gaps are.

1. Before any batch runs, it is necessary to verify the identity readiness. This includes UPN alignment, Entra ID attributes, and Azure AD Connect synchronization status. Migration failures are most often caused by mismatched identities.

2. Before migration, conduct a mailbox permission audit. Document all delegate access relationships, shared mailbox memberships, and resource mailbox configuration. BitTitan doesn’t automatically carry over these settings in all scenarios.

3. Before domain migration, DNS and mail flow verification is required. MX Records, SPF, DKIM and Autodiscover are all to be verified in the target environment. Silent mail routing problems begin here.

4. Pre-assigning of licenses is required for each user before the mailbox migration. Access failures are caused by licensing gaps, which look like tool errors. They are not.

5. Before the migration batch runs, confirm that all users have received and acknowledged the cutover instructions and the Outlook reconfiguration steps as well as the mobile device enrollment requirements.

PowerShell allows for partial automation of all five checks. These checks still require an experienced engineer who knows how to read the output.

Pre-migration tests are not an overhead. They are the difference between an upgrade that requires 10 support tickets and another that requires 100.

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