Microsoft explained that the issue in the update affects Outlook’s ability to connect to Exchange. The last updated on the Exchange Blog announced that Exchange Server 2010 SP3 Update Rollup 8 has been re-released to the Microsoft download center fixing the regression issue discovered in the first release.
“The update RU8 package corrects the issue which impacted users connecting to Exchange from Outlook. The issue was insulated to the MAPI RPC layer and was able to be isolated to quickly deliver the updated RU8 package. The updated RU8 package is version number 14.03.0224.002 if you need to confirm you have the updated package. The updates for Exchange Server 2013 and 2007 were not impacted by this regression and have not been updated.”
(Security Affairs – Microsoft, Exchange Server)