Changes to msExchangeHiddenFromAddressList attribute not updated against recipient object in Exchange Online

Original KB number: 4042820

Symptoms

Consider the following scenario:

In this scenario, the changes are not updated against the recipient object in Microsoft Exchange Online.

This issue occurs due to one of the following reasons:

The Alias (MailNickname) attribute on the source object that's located in on-premises doesn't have the required value.
A sync rule in Microsoft Entra Connect has a scoping filter that states that the Operator of the MailNickName attribute is ISNOTNULL. The rule sets Link Type to Join for syncing Exchange attributes together and uses the name In From AD - User Exchange.

To resolve this issue, follow these steps:

Start PowerShell as an administrator on any domain controller or any server that has Remote Server Administrator pack installed. To determine whether any Active Directory module is present on the server, run the following cmdlet:
```
Get-Module -ListAvailable activedirectory
```
Import the Active Directory module for PowerShell versions earlier than 3.0. To do this, run the following cmdlet:
```
Import-Module activedirectory
```
For PowerShell module 3.0 and later versions, the module will load automatically based on the commands that are issued.

Validate that the mailnickname attribute is not set to any value. To do this, run the following cmdlet:

Get-ADObject -Filter {Name -eq ObjectName} -Properties * | Out-String -Stream | Select-String mailnickname

Set the value of the mailnickname attribute to a value that corresponds to the information in the ms-Exch-Mail-Nickname Attribute.
```
Get-ADObject -Filter {Name -eq ObjectName } -Properties * | Set-ADObject -add @{mailnickname=AttributeValue}
```

If the issue still persists, check for and resolve data validation errors in your tenant.

Still need help? Go to Microsoft Community.