Yesterday Microsoft released Service Pack 3 for Exchange 2010. You can download Exchange 2010 SP3 here.
We had been told at MEC 2012 that Exchange 2010 SP3 would be required for Exchange 2013 interoperability, and it is. Unfortunately, we learned yesterday that we now need to wait for Exchange 2013 Cumulative Update 1 to complete the coexistence story. Exchange 2013 CU1 is due Q1 2013 -- in other words, within 90 days or so. I expect that it might be sooner.
Exchange 2013 CU1 includes a number of fixes that will make the coexistence story much better and smoother. It will be worth the wait. This will be the first update for Exchange 2013 using the new service strategy and we can expect new CUs every quarter.
The good news is that this gives us time to install Exchange 2010 SP3 in our environments prior to introducing Exchange 2013 to production. It also gives us time to test coexistence in a test lab, or as stated on the EHLO Blog, "Customers can test and validate this update in a representative lab environment prior to rolling out in their production environments as an important coexistence preparatory step before introducing Exchange Server 2013 CU1."
Exchange 2010 SP3 updates the schema version to 14734. The Exchange 2013 schema version is 15137. You can run the following command from a CMD prompt to determine your current Exchange schema version:
dsquery * CN=ms-Exch-Schema-Version-Pt,cn=schema,cn=configuration,dc=domain,dc=local -scope base -attr rangeUpperYou can refer to the Exchange table in the TechNet article, "How to determine the current Active Directory or Exchange Server schema version", to determine your current schema version.
Even if you have no plans to migrate to Exchange 2013 yet, Exchange 2010 SP3 includes several important updates and fixes, as well as allowing you to install Exchange 2010 on Windows Server 2012. This is really huge, since Windows Server 2012 is an amazing platform and Exchange can really benefit from SMB3. And since Windows 2012 includes PowerShell v3, this means that Exchange 2010 should be compatible with that version and the Management Framework 3.0.
SP3 also includes a new Sent Items Management feature for Outlook Web Access. This provides control over whether an item that is "sent as" you, or "on behalf of" you, is copied to your Sent Items folder and to the sender’s Sent Items folder. Before Exchange 2010 SP3, messages that are "sent as" you or "on behalf of" you are copied only to the sender's Sent Items folder.
You can configure the Sent Items Management feature in OWA on the Options page.
Note that RU6 for Exchange 2010 SP2 was also released yesterday. Exchange 2010 SP3 includes all those fixes, plus additional ones. Refer to the EHLO Blog article and TechNet for details.