We have Exchange 2013 with legacy 2007/2010. My 2007 servers are at RU10. one of my sites has a need to replace their edge server and wants to install a 2013 edge server, but the internal 2007 hub server will require RU13 to communicate with the 2013 edge.

Will updating that single hub server to RU10, and leaving the rest of my 2007 environment at RUY10 cause issues?

Tom

We have Exchange 2013 with legacy 2007/2010. My 2007 servers are at RU10. one of my sites has a need to replace their edge server and wants to install a 2013 edge server, but the internal 2007 hub server will require RU13 to communicate with the 2013 edge.

Will updating that single hub server to RU10, and leaving the rest of my 2007 environment at RUY10 cause issues?

Tom

I would not recommend doing this.  Its best practice to have all your exchange servers running at the same patch level.

Hi Tom,

Thank you for your question.

We could make internal Exchange at different CU level, but it didnt recommend by Microsoft, as Hintes said. Because there are some improvements at new CU for us to avoid issue, include communicate between internal Exchange 2007 server.

We could refer to the following link:

https://technet.microsoft.com/en-us/library/aa996719(v=exchg.150).aspx

If there are any questions regarding this issue, please be free to let me know. 

Best Regard,

Jim