On-Prem Error When Editing Cloud Mailboxes

Question

I am having an issue when attempting to edit/add Email Address Types. When I try to edit them in exchange online, I get this error:

"Error executing request. The operation on mailbox "x" failed because it's out of the current user's write scope. The action 'Set-Mailbox', 'EmailAddresses', can't be performed on the object 'x' because the object is being synchronized from your on-premises organization. This action should be performed on the object in your on-premises organization."

This happens on all mailboxes. I can create mailboxes just fine, but I cannot edit the Addresses.

when the Emails are changed in the AD attribute editor it syncs to my on prem exchange server, but not with the online admin console.

I Updated the Entra AD Sync Connector this morning with no luck. Forcing a complete sync also does not work. Entra is not reporting any issues in diagnostics or the Entra Health Check.

Answer 1

Hi @Connor Zagar ,

Welcome to the Microsoft Q&A platform!

This is usually a hybrid deployment configuration issue.

Please check the MRSProxy service. This is required for mailbox movement in a hybrid deployment. You can check and enable MRSProxy using the following PowerShell commands:

Get-WebServicesVirtualDirectory -Identity “Server\EWS (default Web site)” | fl Server,MRSProxyEnabled,WSSecurityAuthentication
Set-WebServicesVirtualDirectory -Identity “Server\EWS (default Web site)” -MRSProxyEnabled $true -WSSecurityAuthentication $true

If enabled, check that the migration endpoint is correct.

For more information on how to deploy, you can refer to：
https://learn.microsoft.com/en-us/exchange/hybrid-deployment/move-mailboxes#enable-mrsproxy-service

M365 service delay issue cannot be ruled out, please check the above issues and try again!

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