|Message:||Unable to move mailbox %1.
The rules on a folder are too big for the destination server.
Folder name: %2; Error code: %3.
The Error event indicates that the Move Mailbox operation failed when it tried to move a user’s mailbox from Microsoft Exchange Server 2007 to Exchange Server 2003 because the user’s mailbox rules are set too high for the destination server.
In Exchange Server 2003, the rule size limit is 32 kilobytes (KB) while in Exchange Server 2007 the rules limit has been increased to a default size of 64 KB per mailbox. The rule limit in Exchange 2007 is now a customizable limit of up to 256 KB per mailbox.
To successfully complete the Move Mailbox operation, do one or more of the following:
If you are not already doing so, consider running the tools that Microsoft Exchange offers to help administrators analyze and troubleshoot their Exchange environment. These tools can help you make sure that your configuration is in line with Microsoft best practices. They can also help you identify and resolve performance issues, improve mail flow, and better manage disaster recovery scenarios. Go to the Toolbox node of the Exchange Management Console to run these tools now. For more information about these tools, see Toolbox in the Exchange Server 2007 Help.