Public Folder replication stops after you introduce new Exchange server.

After the introduction of a new Exchange Server, you do not find the Public Folder replicating between servers.

*******For the purpose of this article, I have created a lab environment with
Old Exchange 2003SP2 box = E2k3.trash.com
New Exchange 2003SP2 box = child-e2k3.complete.trash.com******

Within Exchange System Manager you would find in SMTP Queues messages piling up with the name of second (destination) Exchange server (see picture below)

 How do we check if this message is PF Message stuck in the queue.
1)      Open the SMTP Queue (Queue for Destination Exchange Server)
2)      Click on Find All
3)      Double Click the messages piled up in the find window.
(Message similar to the picture would be mentioned)
**Sender: SourceServerName-IS@yourdomain.com
*Recipients : DestinationServerName-IS@youdomain.com

Now, since we have understood that this message is Public Folder and is getting stuck in the SMTP Queue, how to know what is stopping this message.
(To initiate message tracking - go to Exchange Server properties in ESM. Click on Enable Message Tracking - see picture below)

Now, to track the message within Exchange System Manager
Go to Organization - Tools - Messaging Tracking Center.
Click on Server tab - type your source Server Name - Check Name and close the box.
At Recipients (do not click on the tab)- type the Recipients email address noted while checking the queues.*
At Senders (do not click on the tab) - type the Senders email address noted while checking the queues.**

Adjust the timing and click on Find Now.

You would see messages with the Sender as Public Folder Store (Sender Exchange Server) in find below and email address also changed to Store Name.

(Refer the picture)

Double-Click on any of the messages with Sender as Public Folder Store (Sender Exchange Server) and you would find messages being sent to your smart host server.

So, let us find this smart host server.

Within Exchange System Manager Go to
=>      Organization
=>      Administrative Groups
=>      Your Administrative Group Name
=>      Servers
=>      Your Exchange Server Name
=>      Protocols
=>      SMTP Virtual Server properties.
=>      Delivery tab - Smart Host - Copy this information to a notepad and remove this.

So, you simply remove this Smart Host - create a new SMTP Connector with address space * and place the same Smart Host in it.

Stop and Restart SMTP Service on Source Server and now, you should find the messages flowing through to the destination exchange server.