Cannot Access Public Folders After Migration Exchange 2013 From Lagecy Server

Hello Guys, In this article we are going to have a discussion about an Exchange Server problem 'Cannot Access Public Folder From Legacy Server After Migration into Exchange 2013/2016'. If you are an Exchange Administrator or you might have migrated the Exchange Server Database into newer version ever then you might be familiar with the error. These type of errors are very crucial and not easier to understand as well as resolve. Let's understand it with the help of a scenario.

Scenario: Cannot Access Public Folders From Lagecy Server After Migration

Let's assume that in an Organization all mailboxes have migrated from Exchange Server 2007/2010 to Exchange 2013/2016 but only public folders or shared mailboxes are still remained in legacy Exchange server database.

Now, you have configured the Outlook with Migrated Exchange Server and trying to access their emails. But Outlook continuously prompting for credentials and after entering the credentials it is again prompting. Then in this situation what did you do, you just clicked on cancel button and now you are able to access emails from your mailbox. However, you cannot access shared mailboxes or public folders from older Exchange 2010/2007 database.

Cause of Error: Outlook Keep Asking for Credentials After Migration

This error occurs because of Logon Network Security which is set by default as Anonymous Authentication in Microsoft Outlook. In that case, if you change it by going through connection properties, however it would automatically set as Anonymous Authentication again.

Basically the reason behind it is that ExternalClientAuthenticationMethod and InternalClientAuthenticationMethod is set to Negotiate and InternalClientRequireSsl is set to True by default. You can view these status by running below commands for External hostname as well as internal hostname.

For External Hostname
Get-OutlookAnywhere –Server servername | fl *external*
For Internal Hostname
Get-OutlookAnywhere –Server servername | fl *internal*

Resolution to the Error: Cannot Access Public Folders After Migration Exchange 2013 / 16

To fix or resolve the error 'Cannot Access Public Folders After Migration Exchange 2013', just run below mentioned PowerShell commands stepwise:

Step 1: Run Get-OutlookAnywhere cmdlet command for verifying Outlook Anywhere settings. Below mentioned command would fetch all Outlook Anywhere settings available on Exchange server.

Get-OutlookAnywhere –Server ExchangeServerName
Step 2: Now run below command to change ExternalClientAuthenticationMethod from Negotiate to NTLM.
Get-OutlookAnywhere –Server ExchangeServerName | Set-OutlookAnywhere –ExternalClientAuthenticationMethod NTLM

Step 3: Now run below command to change InternalClientAuthenticationMethod from Negotiate to NTLM.

Get-OutlookAnywhere –Server ExchangeServerName | Set-OutlookAnywhere –InternalClientAuthenticationMethod NTLM
Step 4: Now finally run below command to set InternalRequired SSL to False for Exchange server.
Get-OutlookAnywhere –Server ExchangeServerName | Set-OutlookAnywhere -InternalClientRequiredSSL $False

That’s it, Now the new settings would be easily applied on Microsoft Outlook, whenever the next time it would be synchronized. You can also manually configure it now.

If still you are facing the issue while accessing Shared mailbox from lagecy Exchange, then there could be the chance of Exchange Mailbox corruption. In this case, you have to first repair corrupt Exchange mailbox and then follow above steps for accessing public folder from lagecy server after migration.

That's all, what you have to do to resolve "cannot access public folder after migration into Exchange 2013/2016 from Exchange 2007/2010".

Conclusion

The article was completely based on resolving "Cannot Access Public Folder From Legacy Server After Migration into Exchange 2013/2016" issue. We had the discussion about its cause as well as the methods to get off from this Exchange AutoDiscover and Outlook Anywhere issue. As we saw that the issue was unable to fix from Outlook Email Client, therefore we executed several command for modification or making some changes in OutloookAnywere Authentication settings.