how to resolve MSExchangeTransport 5015 error

Hi @sophia wang,

Welcome to the Microsoft Q&A platform!

Based on your description, Event ID 5105 errors in Exchange 2013 usually indicate routing issues. You can follow these steps to resolve this issue:

1. Make sure that the installation of the new Mailbox Server A has completed successfully without any errors.
2. The routing table may not be updated correctly. To update the routing table, you can restart the Microsoft Exchange Transport service on all Exchange servers.

• Open the Services console by typing "services.msc" in the Run dialog box.
• Locate the Microsoft Exchange Transport service.
• Right-click and select Restart.

3. Make sure that the new Mailbox Server A has the correct DNS entry and that all Exchange servers can resolve each other's fully qualified domain names (FQDN).
4. Make sure that the Send connector and Receive connector are correctly configured to include the new Mailbox server. You can use the Exchange Admin Center (EAC) or the Exchange Management Shell to check this.

Using the EAC:

• Navigate to Mail Flow > Send Connectors.
• Edit each Send connector and make sure that the new Mailbox Server A is listed in the source servers.
• Do the same for the Receive connector (under Servers > Servers > select the server > Receive Connectors).

Using the Exchange Management Shell:

• Run the following command to check the Send connector:

Get-SendConnector | Format ListName,SourceTransportServers

• If it is not listed, add the new Mailbox server to the connector:

Set-SendConnector -Identity “ConnectorName” -SourceTransportServers ServerA,ServerB

Ensure the Receive connector is configured correctly:

Get-ReceiveConnector -Server ServerA

5. Ensure there are no network issues between the servers. You can use the "ping" command to check basic connectivity:

ping <New-MBX-Server-A-FQDN>

Please feel free to contact me if you have any queries.

Best,

Jake Zhang