We have just done a migration from Exchange 2010 to Exchange 2013 and all mailboxes are now running on the 2013 server. Checking the logs on the 2010 server before I decommission it, I have found that the client access log is still logging entries for some of our users:
1/09/2015 0:00:00 exch2010IP HEAD /rpc/rpcproxy.dll Exch2010.###.local:6001 443 ###\user Exch2013IP MSRPC 200 0 0 0
If I shut down the 2010 server, the users who this is logging for don't have any issues with their mail at all, but I see the following being logged on the 2013 server:
1/09/2015 6:07:18 Exch2013IP RPC_IN_DATA /rpc/rpcproxy.dll Exch2010.###.local:6001&CorrelationID=<empty>;&RequestId=a17e028d-9d3f-4f27-86e0-71585cd75a04&cafeReqId=a17e028d-9d3f-4f27-86e0-71585cd75a04; 443 ###\user 192.168.2.104 MSRPC - 503 0 64 63170
1/09/2015 6:07:20 Exch2013IP RPC_OUT_DATA /rpc/rpcproxy.dll Exch2010.###.local:6001&CorrelationID=<empty>;&RequestId=d95ce424-0a0e-45d5-baf2-72e196f1e511&cafeReqId=d95ce424-0a0e-45d5-baf2-72e196f1e511; 443 ###\user 192.168.2.104 MSRPC - 503 0 64 21027
When I did the migration I did have the two servers running in co-existence with a receive connector on the 2010 server for mail from the 2013 server. Once all the mailboxes were all migrated across, both servers are using the same autodiscover and outlook anywhere url, but all the dns records were updated to point to the new server.
Is there something I have missed in the migration that would be causing some users to be trying to still hit the 2010 server for RPC?