What are the steps to be followed when we are migrating all the emails to a new domain in office 365. Old domain and new domain are in the same tenant.

Question

What are the steps to be followed when we are migrating all the emails to a new domain in office 365. Old domain and new domain are in the same tenant.

Answer 1

Hi Kiran Kumar Imandi,

Appreciate your query over the Microsoft Q&A platform.

When migrating emails from one domain resident in an Office 365 domain to another, careful planning is key to ensuring success. Using the guidelines below will allow you to have minimal impact on the users during the change. Ensure that you provide adequate communication to your users and seek to understand their issues throughout the period.

This is how one can migrate emails to a new domain within the same tenant in Office 365:

1. Add the New Domain: In the Office 365 admin center, you will need to add the new domain and then verify it.
2. Change User Email Addresses: To change the email addresses, all you have to do is navigate to Users> Active users, select users, and change their email domain to the new one.
3. Update DNS Records: Make sure that the DNS records for the new domain are pointing in the correct direction to Office 365.
4. Communicate Changes: Change the users to the new email addresses and tell the user if there is anything that they need to do.

To migrate all emails to a new domain in Office 365 while both the old and new domains are in the same tenant, follow these detailed steps:

1. Prepare the New Domain
   • Add the New Domain: Start by logging into the Office 365 admin center. From there, go to Settings and then select Domains. Click on Add domain and follow the on-screen instructions to incorporate your new domain.
   • Verify the Domain: To confirm that you own the new domain, you’ll need to create specific DNS records (like TXT records) with your domain registrar.
2. Update User Email Addresses Change User Email Addresses:
   • In the admin center, go to Users and then Active users.
   • Select the users whose email addresses you want to update.
   • Click on Manage email aliases and add the new email address, making sure to set it as the primary one.
   Bulk Update: If you have a large number of users to update, you might find it easier to use a CSV file to make bulk changes to email addresses through PowerShell.
3. Update DNS Records Configure DNS Settings: First, make sure that the DNS records for your new domain are correctly configured to work with Office 365. Here’s what you need to do:
   • MX Records: These are essential for directing emails to your new domain.
   • Autodiscover Records: This helps Outlook clients find the new mailboxes easily.
   • TTL Settings: Adjust the TTL settings for your DNS records to help minimize any downtime during the transition.
4. Communicate Changes to Users
   • Notify Users: It’s important to inform all users about the upcoming changes. Let them know their new email addresses and any actions they need to take.
   • Provide Instructions: Offer clear guidance on how to access their new email addresses and explain any changes in the login process.
5. Migrate Existing Emails
   • Email Migration: If users need to keep their old emails, make sure that all their existing emails are accessible under their new email addresses.
6. Test the New Setup
   • Verify Email Flow: After you’ve updated the DNS records, test to ensure that emails are being delivered to the new domain as expected.
   • Check User Access: Finally, confirm that users can log in with their new email addresses and access their mailboxes without any problems.

By following these steps, you will be able to migrate emails to a new domain in M365.

If you have any additional questions, please let us know in the comments. We’re happy to assist further. 

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