Spotted this in the partner forum....
Got Public Folder replication issues? Check this post out:
To troubleshoot the issue, I suggest you perform the following steps:
1. On Exchange 2003 server, open Exchange System Manager->expand "Administrative Group"->"Servers"->"ServerName"->"storage group name"->right click the mailbox store and click "Properties"->go to "Diagnostics logging" tab->in the left panel, expand "MSExchangeIS" and click "Public Folder"->in the right panel, select the following items and make sure the logging level is set to "Maximum":
Replication Incoming message, Replication Outgoing message, Replciation AD Updates, Non-Delivery reports, Replication Backfill, Replication General.
2. On Exchange 2010 server, open Exchange Management Shell and run the following commands to set the event log level:
Set-EventLogLevel –Identity "MSExchangeIS\9001 Public\Replication Incoming Messages" -Level Expert
Set-EventLogLevel –Identity "MSExchangeIS\9001 Public\Replication Outgoing Messages" -Level Expert
Set-EventLogLevel –Identity "MSExchangeIS\9001 Public\Replication DS Updates" -Level Expert
Set-EventLogLevel –Identity "MSExchangeIS\9001 Public\Replication Backfill" -Level Expert
Set-EventLogLevel –Identity "MSExchangeIS\9001 Public\Replication NDRs" -Level Expert
Set-EventLogLevel –Identity "MSExchangeIS\9001 Public\Replication Genera" -Level Expert
3. In SBS 2011 Exchange Management Shell, navigate to "C:\Program Files\Microsoft\Exchange Server\V14\Scripts" and run the following two commands:
.\AddReplicaToPFRecursive.ps1 -TopPublicFolder "\" -ServerToAdd Exchange2010ServerName
.\AddReplicaToPFRecursive.ps1 -TopPublicFolder "\NON_IPM_SUBTREE" -ServerToAdd Exchange2010ServerName
Please wait and monitor the issue. If the issues persists, please collect application log on both Exchange 2003 and Exchange 2010:
If even Public Folder hierarchy doesn't replicate to SBS 2011, it is probably the mail flow has some problems or the SMTP address of SBS 2011 public folder database is not correct. Please perform the following steps to further troubleshoot the issue:
1. Log on Exchange 2010 server, click "Start"->click "Run" and type "adsiedit.msc"
2. Expand the "CN=Configuration,DC=[Domain_Name],DC=com"-> " CN=Services"->"CN=Microsoft Exchange"->"CN=<organization name>"->"CN=Administrative Groups"->"CN=Exchange Administrative Group (FYDIBOHF23SPDLT)"->"CN=Databases"
3. Right click the Public Folder database object and click "Properties"->Make sure the following attribute is set correctly:
ProxyAddresses: "SMTP:PFDatabaseName@domain.com" (For example: the database name is PFDB1, the SMTP address is "SMTP:PFDB1@domain.com")
4. Please try to send an e-mail from a user whose mailbox is on SBS 2003 to SBS 2011 user and check whether the recipient is able to receive the e-mail.
P.S. also ! Remove AV for Exchange on the source. !
Check the following for other known issues: