Outlook Connection Failure While Migrating Exchange Mailboxes

Outlook Error

Users having MS Outlook configured to Exchange 2010 mailboxes and using Cached Exchange mode encounter an issue while trying to relocate the mailboxes to Exchange 2013. The application prompts to restart but later on it fails to establish connection with the Exchange Server Mailboxes and returns an error. Users while migrating from Exchange 2010 to Exchange 2013 usually face this situation. But surprisingly Outlook Web Access users don’t face any changes as compared to MS Outlook desktop version. This occurs due to the following reasons:

•  Outlook gets correctly configured automatically but now with Exchange 2013, the RPC Endpoint is no more pointing towards the original mailbox Exchange 2010 server. Remote Procedure call method is used to establish connection with Exchange Server while using the Outlook application. 
  The client machine or the machine where we are currently using Outlook sends a user defined query to the server along with arguments. The Exchange server analyzes & generates a response message consisting argument/query execution result. 
  As soon as we change the location of the mailbox of the Server, the RPC endpoint doesn’t remain the same, it is now treated as a string with the mailbox GUID and the primary SMTP domain information.
  

  RPC Endpoint

•  The reason that Outlook anywhere is connected is that Exchange 2013 uses RPC over HTTPS connection for both inside and outside connection as compared to the older versions.

  

  CAS Architecture for Exchange 2013

Outlook displays the status of disconnected mailbox from the Exchange Server. These issues persist until the user updates his Outlook application to the later versions or selectively go for Outlook 2013 update 2863911 available online.

Manual Resolution:

Method #1: Use Outlook To Repair The Exchange Email Account

• Repairing the Exchange Server mailbox sometimes resolves the issue when configuration and other settings are correct & still issue is posted.
•  Open Outlook
• Navigate to File menu and then Account Settings.
• Select the Exchange Server mailbox and click on the repair option.
• Now proceed by clicking next on the Repair Account dialog box.
• Finish the configuration process and then restart Outlook.
• After finishing Outlook might return Work offline status, navigate to send/receive ->Work Offline and then toggle on or off to manage the changes.

  

  Repair Exchange Mailbox Files

Method #2: Create A New MS Outlook Profile

• Open Outlook
• Click on mail->Show Profiles
• Now click on Add button and then specify a profile name.
•  Configure the newly created Outlook profile by mentioning the username, SMTP addresses and then the passwords.
•  Finish the setup by clicking next and Finish Button.
• Ensure that Always use this profile option is checked to set this newly created profile as default and use the currently defined settings.

Create New Profile

Method #3: Relocating The Mailboxes

Temporarily move the mailbox to another location or the original server. Reverting back to the original mailbox server is sometimes beneficial as then we could make out that the original mailbox database got corrupted on its way through the migration process or the exchange 2013 server settings aren’t getting properly configured to Outlook.

Method #4: Resolve the Issue Using Power Shell Commands

Power Shell

Add Active directory permissions along with CAS Server permissions which would enable users to access Exchange mailboxes in case they were denied earlier due to absence of the same.

•       Get-ClientAccessServer ExchangeServerName | Add-AdPermission -AccessRights ExtendedRight -ExtendedRights "ms-exch-epi-token-serialization" -User "Domain\Exchange Servers"
•      Get-MailboxServer ExchangeServerName | Add-AdPermission -AccessRights ExtendedRight -ExtendedRights "ms-exch-epi-token-serialization" -User "Domain\Exchange Servers"

Method #5: Usage Of Mailbox Replication Service

It is amongst the most import tools as it allows movement of mailboxes between databases. Mailbox replication service runs on CAS Servers. Instead of directly moving the mailbox data between two different server versions, we should take the help of mailbox replication service. It is much better approach and doesn’t result in any form of error .MRS is simple as here we are working with the Active Directory attributes for mailboxes that are being moved. The XML data that describe the move requests that Exchange stores in system mailboxes within databases. In fact with MRS you aren’t doing much, thus saving complexity and eliminating any source of error.

Mailbox Replication

 MRS operations are operated by an XML  MSExchangeMailboxReplicationService.exe.config file that is located at the /bin directory , the service reads that configuration file whenever it is executed.

Conclusion:

Exchange Server 2010 to 2013 migration process comes up with multiple issues and one of the problematic issues is Outlook connection failed issue. It can be easily resolved by creating a new Outlook profile, relocating the mailboxes, usage of Power Shell commands or the most optimal solution is to prefer usage of Mailbox replication service instead at the first place.

Before performing any changes ensure that you maintain a fresh copy of the mailbox database and then use replication service to first replicate the mailbox to the migrating server and then after completion of the process, eradicate the older Server contents. Relocating each and every mailbox database can cause several issues as Outlook have different settings for lower Exchange versions as compared to later ones. Hence they create issues while accessing the mailbox using OWA or Outlook.