December 2016 Updates Released For All Versions of Exchange Server

Microsoft has released new updates for all supported versions of Exchange Server, announcing:

Cumulative Update 4 for Exchange Server 2016 (download | UM language packs)
Cumulative Update 15 for Exchange Server 2013 (download | UM language packs)
Update Rollup 16 for Exchange Server 2010 SP3 (download)
Update Rollup 22 for Exchange Server 2007 SP3 (download)

The Exchange 2010 and 2007 updates contain daylight saving time fixes, as both of those versions of Exchange are in extended support now.

A public folder indexing issue experienced by some customers who upgraded to Exchange 2013 CU14 or Exchange 2016 CU3 last quarter are now fixed in these latest releases for those two versions of Exchange. Microsoft’s advice is:

To ensure all public folders are indexed appropriately, all public folder mailboxes should be moved to a new database after applying the appropriate cumulative update released today.

When Exchange 2016 CU3 was released, it became the first version of Exchange to support installation on Windows Server 2016. Shortly after that release it was discovered that there was a bug with Exchange 2016 DAG members running on Windows Server 2016 that would result in repeated crashes of IIS on the server. The Windows Server team has released an update that fixes the underlying issue, and all Exchange 2016 deployments on Windows Server 2016 require that update to be installed.

Both Exchange 2013 and 2016 now also support .NET 4.6.2, and Microsoft encourages you to deploy .NET 4.6.2 as soon as possible, because it will be the required version for Exchange 2013/2016 releases from March 2017 onwards.

For user-facing changes, Exchange 2016 CU4 also includes an update to the Outlook on the web (OWA) UI to align with the latest experience in Exchange Online, with a new compose interface that moves a bunch of stuff around and forces us to retrain our muscle memory