Exchange Public Folder MESO Object Not Deleted

Problem

When you mail enable an Exchange legacy public folder, a system object is created in Active Directory, which is stored in the so-called MESO object container.

• CN=Microsoft Exchange System Objects, DC=MCSMEMAIL, DC=DE

The object created contains all required attributes for Exchange address lists and other Exchange attributes.

When you mail disable a public folder Exchange Server is supposed to delete the MESO object. For some reason, that might not happen. In this case, the public folder will show in Public Folder Management Console as mail disabled but can still receive emails sent to its email address.

From an Exchange perspective, the email address can still be resolved because a system object containing the email address still exists.

At first, it looked like a permission issue on the MESO object container, but it wasn’t.

Solution

A Microsoft KB article described the issue for a single forest, multi-domain environment, and a similar issue with Exchange Server 2010.

Configure the following registry on each Exchange Server hosting a public folder database and restart the MSExchangeIS service.

• HKEY_LOCAL_MACHINESystemCurrentControlSetServicesMsExchangeISParametersSystem
• DWORD (32 bit)
• EnableDeletePFProxyAndStorePropTogether
• Value = 1

In addition, you should name the public folder and domain controller in the Exchange cmdlet

Enable-MailPublicFolder “Public Folder Name” –Server PUBLICFOLDERSERVER –DomainController DC01

When you mail enable an existing public folder that looks like being mail disabled but still has an (old) MESO object, a new MESO object will be created. The situation will be as follows:

• Old MESO object attributes
  • displayName=Public Folder Name
  • CN=Public Folder Name
  • mail=PublicFolderName@mcsmemail.de
• New MESO object attributes
  • displayName=Public Folder Name
  • CN=Public Folder Name 38513598
  • mail=PublicFolderName2@mcsmemail.de

The result is not necessarily as expected, as the old MESO object is orphaned and never reconfigured again.

Orphaned objects need to be cleaned up manually and recreated again if necessary. In an Exchange environment that has been migrated from ancient versions to 2010, you might already have many MESO objects with digits added to their common names.

You can clean up the MESO objects as follows:

1. Delete orphaned objects in the MESO container
2. Mail enable public folder

This results in a correctly named and configured MESO object. You can use Bill Long’s PowerShell script to identify orphaned public folder objects in the MESO container.

Note

This information is related to legacy Exchange public folders hosted on Exchange Server 2007 and/or Exchange Server 2010.

The solution has also been validated for Exchange Server 2007, even though the KB article has been published for Exchange Server 2010 only.

Links

• KB2647396: A public folder still appears in Exchange address lists after you mail-disable the folder in an Exchange Server 2010 environment
• Bill Long: Cleaning up Microsoft Exchange System Objects – part 2

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This post had originally been posted on my former blog SF-Tools.

Do you need assistance with your Exchange Server setup? You have questions about your Exchange Server infrastructure and going hybrid? You are interested in what Exchange Server 2019 has to offer for your environment?

Contact me at thomas@mcsmemail.de
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