Onboarding | Project Phases | Best Practices | Glossary of Key Terms

Post-cutover configuration

It’s important to understand what applications and services must be reconfigured after your Cutover to ensure mail delivery to all required devices. Configuration of desktop applications (i.e. local Outlook) and mobile devices is to be performed by the customer.

Key terms

• Post-cutover: the period of time following the transition to the new platform. Generally speaking, this is Day 1 in the new environment.

Outlook Client Reconfiguration

If you synced a local Outlook client to your source account, and want to now sync it your target account, it is required that you reconfigure your Outlook profile when transitioning to a new platform.

When Outlook Client Reconfiguration Is Required

Outlook client reconfiguration is required when:

• Your mailbox was migrated between Microsoft 365 tenants
• The UPN, tenant ID, or mailbox GUID changes
• Outlook continues trying to authenticate to the old tenant

Important: Simply re-entering credentials is usually insufficient. A new Outlook profile and cache cleanup are required.

Follow these step-by-step instructions to reconfigure your local Outlook client so it properly syncs to your target mailbox:

• Outlook Client Reconfiguration Process (Windows)

• Outlook Client Reconfiguration Process (Mac)

Other Considerations

Users should begin using their target accounts after the Cutover. Depending on the user, this may require the following:

• Using a new URL and login credentials to access the new mailbox via a browser.

• Removing the old account from Outlook and replacing it with the new one.

• Updating mobile apps to point to new mailboxes.

• If a file migration is in scope, users will need to re-share all or select files or folders that were shared with internal or external users in the source platform.

• Users reporting issues with their mail, calendar, contacts or tasks must verify the problem exists when accessing their mailbox through a supported web browser. Problems reported in a desktop client or mobile device may be the symptom of synchronization issues unrelated to the data migration.