Error received in the Target Agent log file during Public Folders synchronization:
"CMessage::CopyFromPST Error -2147467259 A rule in this public folder prevents a message this large from being posted. - MAPI_E_CALL_FAILED (Microsoft Exchange Server Information Store) Low level error: 0x4D4 File: 'aeCopyMsg.cpp' Line: '1463' (Subject: '5E6E6CBABE0E8C46A7281195D834DD7E000000A21884', SourceKey: '5E6E6CBABE0E8C46A7281195D834DD7E000000A21884')"
On every Exchange 2003 server installation, the maximum item size for Public Folder is set to 10240KB (10MB) by default. This actual setting is held on the messageSizeLimit attribute on each Public Folder Store object in the Active Directory.
Refer to Microsoft KB Article ID: 818474 - "Overview of Security-Enhanced Settings in the Default Configuration of Exchange Server 2003" for more information about default Exchange 2003 configuration:
These setting can be adjusted or removed on the Limits tab under the Properties of Public Folder Store in Exchange System Manager.