MailNickName or Alias attribute in Exchange Online doesn't match what is set in Exchange on-premises

مقالة
01/24/2024
ينطبق على:

Exchange Online, Microsoft Exchange Online Dedicated

Symptoms

The Alias or Mailnickname attribute in Microsoft Exchange Online doesn't match what is set in the Exchange on-premises environment for a synced user account.

Cause

This issue occurs if changes are made to the user principal name (UPN) for the user and the Mailnickname attribute value is changed to the prefix of the UPN.

Resolution

To resolve this issue, update the Alias or Mailnickname attribute. To do this, use one of the following methods.

Method 1: Use Exchange Management Shell

Change the existing Alias attribute value so that the change is found by Microsoft Entra Connect. This should sync the change to Microsoft 365. To do this, use either the Set-Mailbox or Set-RemoteMailbox cmdlet, based on the recipient type in Exchange on-premises.
- Set-RemoteMailbox
```
$alias=Get-remotemailbox <user@domain.com>
Set-RemoteMailbox <user@domain.com> -alias "$($alias.alias)1"
```
- Set-Mailbox
```
$alias=Get-mailbox <user@domain.com>
Set-Mailbox <user@domain.com> -alias "$($alias.alias)1"**
```
Start a Delta sync from Microsoft Entra Connect, or wait for Microsoft Entra Connect to run the delta. Ideally, this should sync the changes that are made in step 1 to Microsoft 365.

Change the value of the Alias attribute to its original value. To do this, run either of the following cmdlets:

Set-RemoteMailbox <user@domain.com> -alias "$($alias.alias)"

Set-Mailbox <user@domain> -alias "$($alias.alias)"

Start a Delta sync from Microsoft Entra Connect, or wait for Microsoft Entra Connect to run the delta> Ideally, this should sync the changes to Microsoft 365.

Method 2: Use Active Directory PowerShell module

Change the Mailnickname attribute value so that the change is discovered by Microsoft Entra Connect. This should sync the change to Microsoft 365. To do this, run the following set of cmdlets:

$mailnickname=Get-ADUser -Properties * -Filter {name -like '<username>*'}
Get-ADUser -Properties * -Filter {name -like '<username>*'} | set-aduser -replace @{mailnickname="$($mailnickname.mailnickname)1"

Start a Delta sync from Microsoft Entra Connect, or wait for Microsoft Entra Connect to run the delta. Ideally, this should sync the changes that are made in step 1 to Microsoft 365.

Change the value of the Mailnickname attribute to its original value. To do this, run the following cmdlet:

Get-ADUser -Properties * -Filter {name -like '<username>*'} | set-aduser -replace @{mailnickname="$($mailnickname.mailnickname)"

Start a Delta sync from Microsoft Entra Connect, or wait for Microsoft Entra Connect to run the delta. Ideally, this should sync the changes that are made in step 1 to Microsoft 365.