Send As permissions after mailbox migration to Exchange online.

Question

I am going to migrate a user mailbox from On-prem to exchange online. I have two queries.

1. User has Full and SendAs permission to another service mailboxes. So once I'll complete the migration to cloud, I know sendAs permission not going to work, but can user still send with SendAs permission as there is full access as well to same mailbox?
2. User has in-place archive in on-prem exchange, I can't find to include that Archive in migration wizard.

Thanks Vijay

Answer 1

Hi @ Vijay Kumar ,

1.Azure AD Connect doesn't automatically synchronize Send As permission between on-premises Exchange and Microsoft 365 or Office 365, so cross-premises Send As permissions aren't supported. However, you can manually add Send As permission in both environments, as described at this link：Permissions in Exchange hybrid deployments | Microsoft Learn

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2.If you enabled the archive mailbox before migration, the archive mailbox is migrated to the cloud together when the primary mailbox is migrated. If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

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Answer 2

Hi @ Vijay Kumar ,

1.A mailbox on an on-premises Exchange server can be granted the Full Access permission and the Send on Behalf permission  to a Microsoft 365 or Office 365 mailbox, and vice versa.

However, you need to  make some changes to the Azure Active Directory Connect server to synchronize Send on Behalf permissions between the on-premises Exchange server and Exchange Online.

(Note: Outlook on the web doesn't support cross-premises mailbox permissions.)

For more information, see this article：Permissions in Exchange hybrid deployments | Microsoft Learn

 

2.According to this document, if you enabled archive mailboxes before migration, archive mailboxes can be migrated to Microsoft 365 along with your primary mailbox：

Can't migrate on-premises archive mailboxes to Microsoft 365 in a hybrid migration - Office 365 | Microsoft Learn

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If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

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Answer 3

Hi Laing Thanks for sharing information.

1. So once I migrate user mailbox to office 365, with full access user will be able to send as a mailbox which is on-prem? or additional settings require to fix SendAs.
2. I will enable online archive for user before migration. The question I was asking, like I don't see any word with 'Archive' in migration wizard. So once I enable archive in office 365, migration wizard will automatically include any archive mailbox if user has one in on-prem exchange?

Thanks Vijay

Answer 4

I am not sure how to enable archive mailbox before migration. Because mailbox doesn't exist in exchange online, it only exists as contact.