During to transition to newer version of Exchange from Exchange 2007, receive connector might include lots of IP addresses and ranges which you want to transfer to your new server. While you can find some scripts on the web which let you export IP addresses to txt file and import it from that same file on your new server, the easiest way to do this is to pipeline with PowerShell.
Set-ReceiveConnector ”SERVERNAME2\CONNECTORNAME” -RemoteIPRanges ( Get-ReceiveConnector “SERVERNAME1\CONNECTORNAME” ).RemoteIPRangesWhere SERVERNAME2 is the name of your new HUB server and SERVERNAME1 is the name of your old server from where you want IP addresses to be extracted.
Information provided thanks to: http://scottsitramblings.wordpress.com/2011/06/23/copypaste-send-or-receive-connectors-exchange-2010/
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