Merge on premises and o365 mailbox

Merging on-premises and Office 365 mailboxes involves integrating the two environments to provide a seamless user experience. Here's a step-by-step guide to help you achieve this:

Prerequisites:

  1. You have an existing on-premises Exchange organization.
  2. You have an Office 365 tenant with Exchange Online.
  3. You have a hybrid deployment setup (if not, you can set it up using the Microsoft Hybrid Configuration Wizard).

Step 1: Prepare your on-premises environment

  1. Ensure that your on-premises Exchange organization is running Exchange 2013 or later.
  2. Verify that your on-premises Exchange organization is configured for hybrid deployment.
  3. Make sure that your on-premises Exchange organization is synchronized with Azure Active Directory (AAD) using Azure AD Connect.

Step 2: Prepare your Office 365 environment

  1. Ensure that your Office 365 tenant is running Exchange Online.
  2. Verify that your Office 365 tenant is configured for hybrid deployment.
  3. Make sure that your Office 365 tenant is synchronized with AAD using Azure AD Connect.

Step 3: Migrate mailboxes

You can use the following methods to migrate mailboxes from on-premises to Office 365:

  1. Cutover migration: This method involves migrating all mailboxes at once, and then switching the DNS records to point to Office 365. This method is suitable for small to medium-sized organizations.
  2. Staged migration: This method involves migrating mailboxes in batches, and then switching the DNS records to point to Office 365. This method is suitable for larger organizations.
  3. Hybrid migration: This method involves migrating mailboxes from on-premises to Office 365 using the Microsoft Hybrid Configuration Wizard. This method is suitable for organizations with a mix of on-premises and cloud-based users.

Step 4: Configure mailbox routing

After migrating mailboxes, you need to configure mailbox routing to ensure that mail flows correctly between on-premises and Office 365. You can use the following methods:

  1. Hybrid Mailbox Routing: This method involves configuring mailbox routing using the Microsoft Hybrid Configuration Wizard.
  2. Transport Rules: This method involves creating transport rules to route mail between on-premises and Office 365.

Step 5: Verify mailbox functionality

After completing the migration and configuring mailbox routing, verify that mailbox functionality is working as expected. You can use the following methods:

  1. Test mail flow: Send test emails from on-premises to Office 365 and vice versa to verify that mail is flowing correctly.
  2. Verify mailbox access: Verify that users can access their mailboxes from both on-premises and Office 365.

Additional considerations:

  1. Public Folder migration: If you have public folders in your on-premises environment, you'll need to migrate them to Office 365 using the Microsoft Hybrid Configuration Wizard.
  2. Calendar and contact migration: If you have calendar and contact data in your on-premises environment, you'll need to migrate them to Office 365 using the Microsoft Hybrid Configuration Wizard.
  3. Security and compliance: Ensure that your organization's security and compliance policies are aligned with the hybrid environment.

By following these steps, you can successfully merge your on-premises and Office 365 mailboxes, providing a seamless user experience for your users.