Image of a Office 365 tenant to tenant migration

Migrating between tenants on Office 365 requires the move of your current domain names or transition to a new one. We discuss both methods of completing an office 365 tenant to tenant migration.

Migrating between Office 365 tenants while keeping the same domain\s.

There may be times when you need to complete a migration between office 365 tenants and need to take your domain with you, for example, a company buyout. This means you will need to decommission the domain on the current tenant and move it to another. The process below gives you steps on how to achieve this goal.

This type of migration will require some downtime as Microsoft do not allow a domain to exist on more than one tenant at a time. It’s important to keep your staff informed of what will be happening, together with timescales and projected down times.

1) First we need to start preparing the destination tenant account so it’s ready to receive data from your current tenant. Add your domain\s to the destination tenant but at this stage do not verify it\them yet. You will need to also add the requested text record to your DNS to allow it to replicate.

2) Within your DNS setup change the TTL of your MX records to 1 minute.

3) Using the default Office 365 domain ( .onmicrosoft.com ) setup your user accounts on your new destination tenant and assign a license.

4) Make a note of the primary and alias email addresses configured for each user on the source.

5) Now login to your account on our Migration Monster system ( or other Exchange Web Services based solution) and setup a migration project using both the source and destination URL’s as https://outlook.office365.com . You will need to decide if you plan to use admin credentials on the source and destination or use the users credentials to access each mailbox. Using admin credentials removes the requirement to use our credentials collection option or to collect passwords manually.

6) Populate the migration project with the mailboxes you would like to migrate and then start your first migration pass.

7) Once the pass has completed and when you are ready to start your migration switch over. Change your MX records to an unreachable destination so that email starts to queue within the sending mail server. You now have a maximum of 24 hours to complete your migration before email will start to be rejected and NDR (non-delivery reports) will be sent to the sender and emails dropped. After 4 hours’ senders may receive a DSN (Delivery status notification) informing of the message delay. You may prefer to put in place a backup MX provider to hold the emails for longer and with no DSN or NDR messages while the migration takes place.

8) Once the email has been prevented from entering your old tenant account start a second migration pass to copy any residual items over on to your new Office 365 tenant. Check to make sure that all required mailboxes and content have been migrated as specified.

9) To allow you to remove the domain from the source tenant, now delete all users, contacts and groups from the source Office 365 account.

10) Now remove the domain from the source tenant and wait an hour for your changes to replicate.

11) Verify your domain\s on the new tenant that you configured the DNS for in stage 1. If the domain refuses to verify contact Microsoft support. It is quite common for Microsoft to have to manually de-provision before you are able to verify correctly.

12) Once the domains have been added, for each user, you will now need to setup the required email addresses for the domain\s you have verified.  Remember to setup alias’s as well as the primary email address. It is possible to bulk change the primary domain in Office 365.

13) Now wait for one hour to allow the changes made to replicate through Microsoft’s systems.

14) Point your primary MX record back to Office 365 and decommission the backup MX provider if you put this in place.

15) Your o365 to o365 tenant migration is now completed.

Migrating between Office 365 tenants and changing the domain name\s

You may want to migrate users between office 365 tenants and no longer need the current domain or you may prefer to leave the current domain behind until the migration is completed, allowing a slower staged migration.

It’s important to keep you staff informed of what will be happening, together with timescales and projected down times.

1) First we need to start preparing the destination tenant account so it’s ready to receive data from your current tenant. Add your new domain\s to the destination. With this scenario we are migrating to a different domain/s so the domains can be configured in advance and verified. Adding domains to your new tenant will require changes to your DNS setup.

2) Setup your user accounts on your new Office 365 destination tenant and assign a license. You can use your new domain as the default domain as your old domain will not be migrated (at this stage or never)

3) You may wish to make a note of the users name format on the source and replicate it to the new domains on the destination, for example  Firstname.Surname@, Firstname@ or FirstnameLastnameInitial@

4) Now login to your account on our Migration Monster system (or other Exchange Web Services based solution) and setup a migration project using both the source and destination URL’s as https://outlook.office365.com . You will need to decide if you plan to use admin credentials on the source and destination or use the users credentials to access each mailbox.  Using admin credentials removes the requirement to use our credentials collection option or to collect passwords manually.

5) Populate the migration project with the mailboxes you would like to migrate and then start your first migration pass. Once completed, mailbox users will see all their mailbox content on the destination system.

6) If you are planning to forward emails from your old domain to your new domain then configure this now so that email is forwarded correctly and does not continue to enter the mailboxes on the old tenant. This can be accomplished by placing forwarding on the source mailboxes to the new domain. Now start a second migration of mailboxes set to forward mail, to copy any residual items over on to your new Office 365 tenant. Check to make sure that all required mailboxes and content have been migrated as specified.

7) Your office 365 to office 365 migration is now complete.

Also read, Office 365 Pre-Migration & Post-Migration Checklist [2019]

Please note: – If leaving the old domain behind you may wish to convert the source mailboxes to forwarding contacts post-migration for whatever period is needed.
– If you plan to move the old domain across from the old tenant after the migration. To remove the domain from the source tenant, now delete all users, contacts and groups from the source Office 365 account. This will allow you to then delete the domain from the source tenant and add it to the new tenant. If the domain refuses to verify on the new tenant, contact Microsoft support. It is quite common for Microsoft to have to manually de-provision before you are able to verify correctly.

We hope this article helps with your tenant to tenant migration.

If you would like to give Migration Monster a try with 4 Free Unrestricted Mailbox Migrations please go to https://www.migration-monster.com/office-365-migration-tool-trial

Migration Monster Team

https://www.migration-monster.com

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