Download OAB for non-domain joined computer in Exchange 2010

Hi All,

I am setting up an environment to migrate Exchange 2003 to Exchange 2010, all things is running smooth except I cannot download OAB internally for client that are using non-domain joined computer. (External is not tested as the IP is not ready)

Background of the Exchange environment:

Exchange 2003 x1
Exchange 2010 x2 (set as CAS Array without NLB and DAG group member)

When I tried to download OAB by pressing "Send/Receive" button in Outlook (2007 / 2010), error message is prompted as below:
"Microsoft Exchange has reported an error (0x8004010F): Object not found"

In the "Sync Issue" folder, error message:
Cannot find URL
0x8004010F

I have run the command:

Set-AddressList “All Users” –IncludedRecipients MailboxUsers
Set-AddressList “All Groups” –IncludedRecipients Mailgroups
Set-AddressList “All Contacts” –IncludedRecipients MailContactsSet-AddressList "Public Folders" -RecipientFilter { RecipientType -eq 'PublicFolder' }
Set-GlobalAddressList "Default Global Address List" -RecipientFilter {(Alias -ne $null -and (ObjectClass -eq 'user' -or ObjectClass -eq 'contact' -or ObjectClass -eq 'msExchSystemMailbox' -or ObjectClass -eq 'msExchDynamicDistributionList' -or ObjectClass -eq 'group' -or ObjectClass -eq 'publicFolder'))}

When I try to test the autodiscover, it is running successfully for domain joined computer but not non-domain joined computer.

Non-domain joined: 
Autoconfiguration has started, this may take up to a minute
Autoconfiguration was unable to determine your settings.

Is there anything I need to configure in DNS for my non-domain joined computer?

Please advise.

Thanks,

Jack Chan