Domain Transfer in M365 Tenant

Question

Hi Team

We have migrated mailboxes from a domain called Domain A(Source) into Domain B(Destination).

Please note:Domain A and Domain B both are in M365 Tenant.

I am looking to remove domain A from Source -M365(then Shut down) and add Domain A to my MS 365 Tennant(Destination)

I assume the movement of Domain to Destination MS365 tenant is to retain the domain name and be able to use the SMTP(Alias)  mask on the mailboxes migrated into Domain B.

Could you please help with Steps to remove domain A (M365-Source and shut it down) and add Domain A to M365 Destination.

Answer 1

Hi @Saurabh Singh ,

You will have to add and verify the source domain in the target tenant and assign it to the migrated mailboxes as primary SMTP. Please refer to the following links: https://techcommunity.microsoft.com/t5/exchange/cross-tenant-mailbox-migration-step-by-step-guide/m-p/3394075

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Answer 2

1.Change user UPNs to onmicrosoft.com. Always do that step first, before starting removal of email addresses. The step can be easlily automated.

2.Remove email addresses containing vanity domain from user mailboxes, mail users, groups. Again there are scripts on the internet that allow you automated removal.

3.Then in the admin center, go to the Settings > Domains page, select the domain that you want to remove.