Unable to create alias in Office 365

New Contributor


I deleted an Office 365 user more than 30 days ago, and Today I wasn't able to create his email as alias for existing user with the following error:

An Azure Active Directory call was made to keep object in sync between Azure Active Directory and Exchange Online. However, it failed. Detailed error message: Another object with the same value for property EmailAddresses already exists. RequestId : 0c0e19f1-36f0-4ee0-9932-f2e5079eefcf The issue may be transient and please retry a couple of minutes later. If issue persists, please see exception members for more information.

I did search for the old object as mailbox/contact/group using Admin Center/Connect-EXOPSSession/Connect-AzureAD /Connect-MsolService in PowerShell with no success, Also I contacted @AzureSupport / @MicrosoftHelps and they point me to start this discussion, Hopefully I can find the solution here


4 Replies
Use the Get-Recipient cmdlet to find the matching object:

Get-Recipient email@domain.com

@Vasil Michev 

Hello Dear,


This is what I got as response:

The operation couldn't be performed because object 'email@domain.com' couldn't be found on...


I even tried: Get-Recipient email@domain.onmicrosoft.com with no success

Back to support then, as that's most likely an issue on the backend.

@Vasil Michev 

Hello thats not right, proxyaddresses at the local AD is the right way. And thats why u get them is the azure AD Sync is active. Greetz